Metal complexes, comprising carbene ligands having an o-substituted non-cyclometalated aryl group and their use in organic light emitting diodes

ABSTRACT

Cyclometallated Ir complex comprising three N,N diaryl substituted carbene ligands, bearing substituents in the 2 position of the non-cyclometallated aryl ring; an organic electronic device, preferably an organic light-emitting diode (OLED), comprising at least one cyclometallated Ir complex as described above, a light-emitting layer comprising said cyclometallated Ir complex preferably as emitter material, preferably in combination with at least one host material, use of said cyclometallated Ir complex in an OLED and an apparatus selected from the group consisting of stationary visual display units, mobile visual display units, illumination units, units in items of clothing, units in handbags, units in accessories, units in furniture and units in wallpaper comprising said organic electronic device, preferably said OLED, or said light-emitting layer. The present invention further relates to a process for the preparation of said cyclometallated Ir complex.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/300,582, filed Sep. 29, 2016, now allowed, which is a 35U.S.C. § 371 national stage patent application of International PatentApplication No. PCT/EP2015/056491, filed on Mar. 26, 2015, and whichclaims priority to European Patent Application No. 14162085.7, filed onMar. 31, 2014, all of which applications are incorporated by referenceherein in their entireties.

DESCRIPTION

The present invention relates to a cyclometallated Ir complex comprisingthree N,N diaryl substituted carbene ligands, bearing substituents inthe 2 position of the non-cyclometallated aryl ring; an organicelectronic device, preferably an organic light-emitting diode (OLED),comprising at least one cyclometallated Ir complex as described above,to a light-emitting layer comprising said cyclometallated Ir complexpreferably as emitter material, preferably in combination with at leastone host material, to the use of said cyclometallated Ir complex in anOLED and to an apparatus selected from the group consisting ofstationary visual display units, mobile visual display units,illumination units, units in items of clothing, units in handbags, unitsin accessories, units in furniture and units in wallpaper comprisingsaid organic electronic device, preferably said OLED, or saidlight-emitting layer. The present invention further relates to a processfor the preparation of said cyclometallated Ir complex.

Organic electronics, i.e. organic electronic devices, are an importantsector in the field of electronics. Organic electronics is a subfield ofelectronics which uses electronic circuits which comprise polymers orsmaller organic compounds. Fields of use of organic electronics are theuse of polymers or smaller organic compounds in organic electronicdevices, for example in organic light-emitting diodes (OLED),light-emitting electrochemical cells (LEEC), organic photovoltaic cells(OPV) and organic field-effect transistors (OFET).

The use of suitable novel organic materials thus allows various newtypes of components based on organic electronics to be provided, such asdisplays, illumination, sensors, transistors, data stores orphotovoltaic cells. This makes possible the development of new deviceswhich are thin, light, flexible and producible at low cost.

The synthesis and provision of new materials for organic electronicdevices is therefore an important research topic. Especially thesynthesis and provision of dyes for use in organic electronic devices(useful for example as emitter materials in OLEDs and LEECs or asabsorption dyes in OPVs) is important for providing organic electronicdevices having good stabilities and long lifetimes as well as—in thecase of OLEDs and LEECs—high quantum efficiencies.

A preferred field of use according to the present application is the useof relatively small organic compounds in organic light-emitting diodes(OLED). OLEDs exploit the propensity of materials to emit light whenthey are excited by electrical current. OLEDs are of particular interestas an alternative to cathode ray tubes and liquid-crystal displays forproduction of flat visual display units. Owing to the very compactdesign and the intrinsically low power consumption, devices comprisingOLEDs are suitable especially for mobile applications, for example forapplications in cellphones, smartphones, digital cameras, mp3 players,tablet computers, laptops, etc. In addition, white OLEDs give greatadvantage over the illumination technologies known to date, especially aparticularly high efficiency.

The basic principles of the way in which OLEDs work and suitablestructures (layers) of OLEDs are specified, for example, in WO2005/113704 and the literature cited therein.

The light-emitting materials (emitters) used may be phosphorescentmaterials (phosphorescent emitters) as well as fluorescent materials(fluorescent emitters). The phosphorescent emitters are typicallyorganometallic complexes which exhibit triplet emission in contrast tothe fluorescent emitters which exhibit singlet emission (M. A. Baldow etal., Appl. Phys. Lett. 1999, 75, 4 to 6). For quantum-mechanical reasonsup to four times the quantum efficiency, energy efficiency and powerefficiency achieved with fluorescent emitters is possible whenphosphorescent emitters are used.

Of particular interest are organic light-emitting diodes with a goodcolor purity, low operational voltage, high efficiency, high efficacy,high resistance to thermal stress and long operational lifetime.

In order to implement the aforementioned properties in practice, it isnecessary to provide suitable emitter materials. The selection ofsuitable emitter materials has a significant influence on parametersincluding the color purity, efficiency, lifetime and operating voltagesof the OLEDs.

One important class of compounds useful in organic electronic devices,especially in OLEDs, preferably as phosphorescent emitters arecyclometallated transition metal carbene complexes.

Such complexes are described for example in WO 2006/056418 A2, WO2005/113704, WO 2007/115970, WO 2007/115981, WO 2008/000727,WO2009/050281, WO2009/050290, WO2011/051404, US2011/057559WO2011/073149, WO2012/121936A2, US2012/0305894A1, WO2012/170571,WO2012/170461, WO 2012/170463, WO2006/121811, WO2007/095118,WO2008/156879, WO2008/156879, WO2010/068876, US2011/0057559,WO2011/106344, US2011/0233528, WO2012/048266 and WO2012/172482.

The cyclometallated transition metal carbene complexes according to theprior art mentioned above having the general formula MA₃B₃ may bepresent in form of their in many cases not isolatable meridional (mer)isomers and/or in form of their usually thermodynamically preferredfacial (fac) isomers, both having different physical properties.

According to the present application, meridional and facial isomers ofoctahedral transition metal complexes are defined as follows:

In the case of complexes of the composition MA₃B₃, three groups of thesame type can occupy either the corners of one face of the octahedron(facial isomer (fac isomer)) or a meridian, i.e. two of the three ligandbonding points are in trans positions relative to one another(meridional isomer (mer isomer)). For the definition of fac/mer isomersin octahedral metal complexes see, for example, J. Huheey, E. Keiter, R.Keiter, Anorganische Chemie: Prinzipien von Struktur und Reaktivität,2nd, revised edition, translated and expanded by Ralf Steudel, Berlin;New York: de Gruyter, 1995, pages 575, 576.

It is shown in the prior art mentioned above that in the case of carbenecomplexes comprising N-alkyl, N-aryl substituted carbene ligands, themer isomer is formed predominantly which can be transformed into thethermodynamically preferred fac isomer. However, in the case of carbenecomplexes consisting of diaryl substituted carbene ligands thethermodynamically preferred fac isomer is usually formed predominantly.

According to the prior art mentioned above, transition metal complexesbearing carbene ligands are usually prepared according to one of thefollowing three routes:

i) Deprotonation of (aza)benzimidazolium salts;

ii) Transmetallation of silver carbenes;

iii) Producing a carbene starting from the corresponding alkoxyderivative.

However, independently from the method used, in the case of asymmetricdiaryl substituted carbene ligands, wherein both aryl residues are ingeneral suitable for a cyclometallation with the central metal, it isnot possible to influence the cyclometallation in order to achieve onlyone cyclometallation isomer of the carbene complex. The separation ofthe isomers is accompanied by a loss of material associated with lowyields.

US 2012/0305894 A1 relates to a blue phosphorescent compound with highcolor purity and a high efficiency and an organic electroluminescentdevice using the same. The blue phosphorescent compound mentioned in theexample according to US 2012/0305894 A1 is characterized by thefollowing formula:

It is mentioned that the Ir complex shown above is obtained as a majorisomer. However, it is not mentioned in US 2012/0305894 A1 how theformation of cyclometallation isomers may be avoided. Further, fac andmer isomers of the compounds described in US 2012/0305894 A1 are notmentioned.

WO 2012/121936 A2 discloses organometallic compounds comprising animidazole carbene ligand having an N-containing ring fused to theimidazole ring. In particular, the N-containing ring fused to theimidazole ring may contain one nitrogen atom or more than one nitrogenatom. These materials are—according to WO 2012/121936 A2—useful as bluephosphorescent emitters for OLEDs.

WO 2011/073149 A1 relates to metal-carbene complexes comprising acentral atom selected from iridium and platinum, and diazabenzimidazolcarbene-ligands, to organic light-emitting diodes comprising saidcomplexes, to light-emitting layers comprising at least one suchmetal-carbene complex, to a device selected from the group comprisinglighting elements, stationary screens and mobile screens comprising suchan OLED, and to the use of such a metal-carbene complex in OLEDs, forexample as an emitter, matrix material, charge transport material,and/or charge or exciton blocker.

WO 2012/172482 A1 relates to metal-carbene complexes comprising acentral atom selected from iridium and platinum, and specificazabenzimidazolocarbeneligands, to OLEDs (Organic Light Emitting Diode,OLED) which comprise such complexes, to a device selected from the groupconsisting of illuminating elements, stationary visual display units andmobile visual display units comprising such an OLED, to the use of sucha metal-carbene complex in OLEDs, for example as emitter, matrixmaterial, charge transport material and/or charge or exciton blocker. Itis further clear from said document that mer isomers could only beobtained in the case of carbene complexes comprising N-alkyl, N-arylsubstituted carbene ligands, while the examples disclosed concerningcarbene complexes comprising diaryl substituted carbene ligands yieldfac isomers.

The three documents, WO 2011/073149 A1, WO 2011/073149 A1 and WO2012/172482 A1 disclose a number of carbene complexes comprisingN-alkyl, N-aryl substituted carbene ligands. In such carbene complexesonly one cyclometallation isomer is present.

It is an object of the present invention to provide metal-carbenecomplexes having aryl substituted carbene ligands only or mainly in formof their mer isomer. It is a further object of the present invention toprovide metal carbene complexes having diaryl substituted carbeneligands in form of only one or mainly one cyclometallation isomer.

Said metal-carbene complexes having diaryl substituted carbene ligandsare suitable for use in organic light-emitting diodes with a good colorpurity, low operational voltage, high efficiency, high efficacy, highresistance to thermal stress and especially long operational lifetime.

It has surprisingly been found by the inventors of the presentapplication that the mer isomer of metal-carbene complexes having diarylsubstituted carbene ligands usually shows significantly shorter emissiondecay times than the corresponding fac isomer. Thus, the radiativeprocesses can better compete with the non-radiative ones. Consequently,metal-carbene complexes of the present invention, especially the merisomers, exhibit efficient emissions and therefore are well suited asemitter materials for OLEDs with long operational lifetime.

It is now possible to isolate mer isomers of metal-carbene complexeshaving diaryl substituted carbene ligands exclusively or as mainisomers.

Since only one or mainly one cyclometallation isomer is present, theseparation of the isomers which is usually accompanied by a loss ofmaterial associated with low yields is in many cases not necessary.

This object is achieved by a cyclometallated Ir complex of formula (I)

wherein

A¹ is CH or N;

A² is CR¹ or N;

A³ is CR² or N;

wherein in the case that A¹ and/or A³ are N, A² is CR¹;

R¹, R², R³, R⁴, R⁶ and R⁷

are each independently hydrogen; deuterium; a linear or branched,substituted or unsubstituted alkyl radical having from 1 to 20 carbonatoms, optionally interrupted by at least one heteroatom, selected fromO, S and N; a substituted or unsubstituted cycloalkyl radical having atotal of from 3 to 30 carbon atoms; a substituted or unsubstitutedheterocyclo alkyl radical, interrupted by at least one heteroatomselected from O, S and N and having a total of from 3 to 30 carbon atomsand/or heteroatoms; a substituted or unsubstituted aryl radical, havinga total of from 6 to 30 carbon atoms; a substituted or unsubstitutedheteroaryl radical, having a total of from 5 to 30 carbon atoms and/orheteroatoms, selected from O, S and N; or a group with donor or acceptoraction;

preferably, R¹, R², R³, R⁴, R⁶ and R⁷ are each independently hydrogen,deuterium, a linear or branched, substituted or unsubstituted alkylradical, having from 1 to 6 carbon atoms; a substituted or unsubstitutedcycloalkyl radical having a total of from 3 to 12 carbon atoms; anunsubstituted aryl radical, having from 6 to 12 carbon atoms, amonosubstituted aryl radical having from 6 to 18 carbon atoms, adisubstituted aryl radical having from 6 to 18 carbon atoms; anunsubstituted heteroaryl radical, having a total of from 5 to 16 carbonatoms and/or heteroatoms, a monosubstituted heteroaryl radical, having atotal of from 5 to 18 carbon atoms and/or heteroatoms, a disubstitutedheteroaryl radical, having a total of from 5 to 20 carbon atoms and/orheteroatoms; more preferably, the aryl radical or heteroaryl radical areselected from the group consisting of phenyl, pyridyl, pyrimidyl,pyrazinyl, carbazolyl, dibenzofuranyl, dibenzothiophenyl, fluorenyl,indolyl, benzofuranyl and benzothiophenyl wherein the aforementionedradicals may be unsubstituted or substituted by methyl, ethyl, n-propyl,iso-propyl, n-butyl, tert-butyl, sec-butyl, iso-butyl, cyclopentyl,cyclohexyl, methoxy, phenyl or CF₃; a group with donor or acceptoraction, selected from OPh, halogen radicals, preferably F or Cl, morepreferably F; CF₃, CN; or SiR¹⁰R¹¹R¹², preferably SiMe₃, SiPh₃, SiEt₃ orSiPh₂tBu;

R¹⁰, R¹¹, R¹²

are each independently a linear or branched alkyl radical, having from 1to 6 carbon atoms, preferably methyl, ethyl, n-propyl, iso-propyl,n-butyl, tert-butyl, sec-butyl or iso-butyl; a substituted orunsubstituted aryl radical, having from 6 to 12 carbon atoms, preferablyphenyl or tolyl; a substituted or unsubstituted heteroaryl radical,having a total of from 5 to 15 carbon atoms and/or heteroatoms; asubstituted or unsubstituted cycloalkyl radical having a total of from 3to 7 carbon atoms, preferably cyclopentyl or cyclohexyl;

or

R¹ and R², R³ and R⁴ and/or R⁶ and R⁷ may form, independently of eachother, together with the carbon atoms to which they are bonded, asaturated or unsaturated or aromatic, optionally substituted ring, whichis optionally interrupted by at least one heteroatom, selected from O, Sand N, has a total of from 5 to 18 carbon atoms and/or heteroatoms, andmay optionally be fused to at least one further optionally substitutedsaturated or unsaturated or aromatic ring, optionally interrupted by atleast one heteroatom, selected from O, S and N, and having a total offrom 5 to 18 carbon atoms and/or heteroatoms;

R⁵

is a linear or branched, substituted or unsubstituted alkyl radicalhaving from 1 to 20 carbon atoms, optionally interrupted by at least oneheteroatom, selected from O, S and N; a substituted or unsubstitutedcycloalkyl radical having a total of from 3 to 30 carbon atoms; asubstituted or unsubstituted heterocyclo alkyl radical, interrupted byat least one heteroatom selected from O, S and N and having a total offrom 3 to 30 carbon atoms and/or heteroatoms; a substituted orunsubstituted aryl radical, having a total of from 6 to 30 carbon atoms;a substituted or unsubstituted heteroaryl radical, having a total offrom 5 to 30 carbon atoms and/or heteroatoms, selected from O, S and N;or a group with donor or acceptor action;

preferably, R⁵ is a linear or branched, substituted or unsubstitutedalkyl radical, having from 1 to 6 carbon atoms; a substituted orunsubstituted cycloalkyl radical having a total of from 3 to 12 carbonatoms; an unsubstituted aryl radical, having from 6 to 12 carbon atoms,a monosubstituted aryl radical having from 6 to 18 carbon atoms, adisubstituted aryl radical having from 6 to 18 carbon atoms; anunsubstituted heteroaryl radical, having a total of from 5 to 16 carbonatoms and/or heteroatoms, a monosubstituted heteroaryl radical, having atotal of from 5 to 18 carbon atoms and/or heteroatoms, a disubstitutedheteroaryl radical, having a total of from 5 to 20 carbon atoms and/orheteroatoms; more preferably, the aryl radical or heteroaryl radical areselected from the group consisting of phenyl, pyridyl, pyrimidyl,pyrazinyl, carbazolyl, dibenzofuranyl, dibenzothiophenyl, benzofuranyland benzothiophenyl wherein the aforementioned radicals may beunsubstituted or substituted by methyl, ethyl, n-propyl, iso-propyl,n-butyl, tert-butyl, sec-butyl, iso-butyl, cyclopentyl, cyclohexylmethoxy, phenyl, CF₃ or CN; a group with donor or acceptor action,selected from CF₃, CN; or SiR¹⁰R¹¹R¹², preferably SiMe₃, SiPh₃, SiEt₃ orSiPh₂tBu;

X is CH, CD or N;

Y is CR⁸ or N;

R⁸

is hydrogen; deuterium; a linear or branched, substituted orunsubstituted alkyl radical having from 1 to 20 carbon atoms, optionallyinterrupted by at least one heteroatom, selected from O, S and N; asubstituted or unsubstituted cycloalkyl radical having a total of from 3to 30 carbon atoms; a substituted or unsubstituted heterocyclo alkylradical, interrupted by at least one heteroatom selected from O, S and Nand having a total of from 3 to 30 carbon atoms and/or heteroatoms; asubstituted or unsubstituted aryl radical, having a total of from 6 to30 carbon atoms; a substituted or unsubstituted heteroaryl radical,having a total of from 5 to 30 carbon atoms and/or heteroatoms, selectedfrom O, S and N; or a group with donor or acceptor action; preferably,R⁸ is hydrogen, deuterium, a linear or branched, substituted orunsubstituted alkyl radical, having from 1 to 6 carbon atoms; asubstituted or unsubstituted cycloalkyl radical having a total of from 3to 12 carbon atoms; an unsubstituted aryl radical, having from 6 to 12carbon atoms, a monosubstituted aryl radical having from 6 to 18 carbonatoms, a disubstituted aryl radical having from 6 to 18 carbon atoms; anunsubstituted heteroaryl radical, having a total of from 5 to 16 carbonatoms and/or heteroatoms, a monosubstituted heteroaryl radical, having atotal of from 5 to 18 carbon atoms and/or heteroatoms, a disubstitutedheteroaryl radical, having a total of from 5 to 20 carbon atoms and/orheteroatoms; more preferably, the aryl radical or heteroaryl radical areselected from the group consisting of phenyl, pyridyl, pyrimidyl,pyrazinyl, carbazolyl, dibenzofuranyl, dibenzothiophenyl, fluorenyl,indolyl, benzofuranyl and benzothiophenyl wherein the aforementionedradicals may be unsubstituted or substituted by methyl, ethyl, n-propyl,iso-propyl, n-butyl, tert-butyl, sec-butyl, iso-butyl, cyclopentyl,cyclohexyl, methoxy, phenyl, CF₃ or CN; a group with donor or acceptoraction, selected from halogen radicals, preferably F or Cl, morepreferably F; CF₃, CN; or SiR¹⁰R¹¹R¹², preferably SiMe₃, SiPh₃, SiEt₃ orSiPh₂tBu.

The key of the present invention is the provision of Ir carbenecomplexes having diaryl substituted carbene ligands bearing asubstituent at the 2 position of one of the aryl residues bound to oneof the carbene nitrogen atoms. By substitution of the 2 position of thearyl residue, it is possible to obtain metal-carbene complexes havingdiaryl substituted carbene ligands only or mainly in form of their merisomer. Further, cyclometallation of said substituted aryl residue withIr is avoided respectively substantially reduced. Therefore, thespecific cyclometallated Ir complexes of formula (I) according to thepresent invention are present in form of their mer isomer as only orpredominant isomer and in form of only one or mainly onecyclometallation isomer. Additionally, the emission lifetime (emissiondecay time) of said complexes is short and the quantum yields are highto very high. Devices comprising the complexes according to the presentinvention show high efficiency and luminous efficacy as well as lowvoltage and especially long operational lifetime.

In the context of the present invention, cyclometallated Ir complexmeans that the aryl residue substituted to one of the carbene nitrogenatoms (i.e. nitrogen atoms of the of the carbene unit) undergoesmetallation with formation of an Ir-carbon a bond, as shown in thefollowing for a cyclometallated Ir complex of formula (I):

In the context of the present invention, cyclometallation isomer meansthat—in the case of an Ir complex of formula (I)—two cyclometallationisomers (isomer A and isomer B) are possible in principle:

However, since the Ir carbene complex according to the present inventioncomprises at least one carbene ligand bearing a substituent at the 2position of one of the aryl residues bound to one of the carbenenitrogen atoms (R⁵), the formation of the cyclometallation isomer B isavoided respectively substantially reduced.

The 2 position of one of the aryl residues bound to one of the carbenenitrogen atoms in the Ir carbene complex according to the presentinvention is—in the context of the present invention—the positionsubstituted with R⁵.

It has been found by the inventors that a substitution of only one 2position of one of the aryl residues bound to one of the carbenenitrogen atoms is sufficient to provide only or mainly the mer isomerand to avoid or to substantially reduce cyclometallation of said arylresidue with Ir.

In the context of the present invention, the terms aryl radical, unit orgroup, heteroaryl radical, unit or group, alkyl radical, unit or group,cycloalkyl radical, unit or group, cycloheteroalkyl radical, unit orgroup, and groups with donor or acceptor action are each defined asfollows—unless stated otherwise:

In the aryl radicals, heteroaryl radicals, alkyl radicals, cycloalkylradicals, cycloheteroalkyl radicals and groups with donor or acceptoraction mentioned below, one or more hydrogen atoms (if present) may besubstituted by deuterium atoms.

Aryl radicals or substituted or unsubstituted aryl radicals having 6 to30, preferably 6 to 18 carbon atoms (C₆-C₃₀-aryl radicals) refer in thepresent invention to radicals which are derived from monocyclic,bicyclic or tricyclic aromatics which do not comprise any ringheteroatoms. When the systems are not monocyclic systems, the term“aryl” for the second ring also includes the saturated form (perhydroform) or the partly unsaturated form (for example the dihydro form ortetrahydro form), provided that the particular forms are known andstable. This means that the term “aryl” in the present inventionencompasses, for example, also bicyclic or tricyclic radicals in whicheither both or all three radicals are aromatic, and bicyclic ortricyclic radicals in which only one ring is aromatic, and alsotricyclic radicals in which two rings are aromatic. Examples of arylare: phenyl, naphthyl, indanyl, 1,2-dihydronaphthenyl,1,4-dihydronaphthenyl, indenyl, anthracenyl, phenanthrenyl or1,2,3,4-tetrahydronaphthyl. Particular preference is given to arylradicals having a base structure of 6 to 13 carbon atoms, for examplephenyl, naphthyl or fluorenyl, very particular preference is given toaryl radicals having a base structure of 6 carbon atoms.

The aryl radicals or C₆-C₃₀-aryl radicals may be unsubstituted orsubstituted by one or more further radicals. Suitable further radicalsare selected from the group consisting of C₁-C₂₀-alkyl, C₆-C₂₄-aryl andsubstituents with donor or acceptor action, suitable substituents withdonor or acceptor action are specified below. Preferred areunsubstituted aryl radicals, having from 6 to 12 carbon atoms, amonosubstituted aryl radicals having from 6 to 18 carbon atoms ordisubstituted aryl radicals having from 6 to 18 carbon atoms. Preferredsubstituents are C₁-C₂₀-alkyl groups, C₁-C₂₀-alkoxy groups, CN, CF₃,halogen radicals, SiR¹⁰R¹¹R¹², wherein R¹⁰, R¹¹ and R¹² are specifiedbelow or amino groups (NR³²R³³ where suitable R³² and R³³ radicals arespecified below), more preferred substituents are methyl, ethyl,n-propyl, iso-propyl, n-butyl, tert-butyl, sec-butyl, iso-butyl,cyclopentyl, cyclohexyl, methoxy, phenyl or CF₃; a group with donor oracceptor action, selected from OPh, halogen radicals, preferably F orCl, more preferably F; CF₃, CN; or SiR¹⁰R¹¹R¹², preferably SiMe₃, SiPh₃,SiEt₃ or SiPh₂tBu.

Heteroaryl radicals or substituted or unsubstituted heteroaryl radicalshaving a total of 5 to 30, preferably 5 to 20 carbon atoms and/orheteroatoms are understood to mean monocyclic, bicyclic or tricyclicheteroaromatics, some of which can be derived from the aforementionedaryl, in which at least one carbon atom in the aryl base structure hasbeen replaced by a heteroatom. Preferred heteroatoms are N, O and S. Thebase structure of the heteroaryl radicals is especially preferablyselected from systems such as pyridine, pyrimidine and pyrazine andfive-membered heteroaromatics such as thiophene, pyrrole, imidazole,thiazole, oxazole or furan. These base structures may optionally befused to one or two six-membered aromatic radicals. Suitable fusedheteroaromatics are carbazolyl, benzimidazolyl, benzofuranyl,benzothiazolyl, benzoxazolyl, dibenzofuranyl, dibenzothiophenyl, indolylor benzimidazo[1,2-a]benzimidazolyl. Particularly preferred basestructures are pyridyl, pyrimidyl, pyrazinyl, carbazolyl,dibenzofuranyl, dibenzothiophenyl, indolyl, benzofuranyl andbenzothiophenyl.

The base structure may be substituted at one, more than one or allsubstitutable positions, suitable substituents being the same as thosealready specified under the definition of C₆-C₃₀-aryl. Preferred areunsubstituted heteroaryl radicals, having a total of from 5 to 16 carbonatoms and/or heteroatoms, monosubstituted heteroaryl radicals, having atotal of from 5 to 18 carbon atoms and/or heteroatoms and disubstitutedheteroaryl radicals, having a total of from 5 to 20 carbon atoms and/orheteroatoms.

An alkyl radical in the context of the present application is a linearor branched alkyl radical, optionally interrupted by at least oneheteroatom, and having 1 to 20 carbon atoms. Preference is given to C₁-to C₁₀-alkyl radicals, particular preference to C₁- to C₆-alkylradicals. In addition, the alkyl radicals may be unsubstituted orsubstituted by one or more substituents. Preferred substituents areselected from the group consisting of groups with donor or acceptoraction, preferably C₁-C₂₀-alkoxy, halogen, more preferably F,C₁-C₂₀-haloalkyl, e.g. CF₃; deuterium; a substituted or unsubstitutedcycloalkyl radical having a total of from 3 to 30 carbon atoms; asubstituted or unsubstituted heterocyclo alkyl radical, interrupted byat least one heteroatom, selected from O, S and N, and having a total offrom 3 to 30 carbon atoms and/or heteroatoms; a substituted orunsubstituted aryl radical, having a total of from 6 to 30 carbon atoms;or a substituted or an unsubstituted heteroaryl radical, having a totalof from 5 to 30 carbon atoms and/or heteroatoms, selected from O, S andN. Suitable aryl substituents are specified above and suitable alkoxyand halogen substituents are specified below. Examples of suitable alkylgroups are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl andoctyl, and also C₁-C₂₀-haloalkyl-, C₆-C₃₀-aryl-, C₁-C₂₀-alkoxy- and/orhalogen-substituted, especially F-substituted, derivatives of the alkylgroups mentioned, for example CF₃ or CF₂CF₃. This comprises both then-isomers of the radicals mentioned and branched isomers such asisopropyl, isobutyl, isopentyl, sec-butyl, tert-butyl, iso-butyl,neopentyl, 3,3-dimethylbutyl, 3-ethylhexyl, etc. Preferred alkyl groupsare methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, iso-butyl,tert-butyl, CF₃ and CF₂CF₃. Most preferred alkyl radicals are CF₃,methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl, sec-butyl andiso-butyl.

A cycloalkyl radical is understood in the context of the presentinvention to mean a substituted or unsubstituted cycloalkyl radicalhaving 3 to 30 carbon atoms. Preferred are cycloalkyl radicals having 3to 18, more preferably 3 to 12 and most preferably 3 to 7 carbon atomsin the base structure (ring) to understand. Suitable substituents arethe substituents mentioned for the alkyl groups. Examples of suitablecycloalkyl groups, which may be unsubstituted or substituted by theradicals mentioned above for the alkyl groups, are cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl and cyclodecyl. They mayalso be polycyclic ring systems such as decalinyl, norbornyl, bornanylor adamantyl.

A heterocycloalkyl radical or a substituted or unsubstitutedheterocycloalkyl radical having 3 to 30 carbon atoms and/or heteroatomsis understood to mean heterocyclo-alkyl radicals having 3 to 18,preferably 5 to 10 and more preferably 5 to 8 ring atoms, where at leastone carbon atom in the heterocycloalkyl base structure has been replacedby a heteroatom. Preferred heteroatoms are N, O and S. Suitablesubstituents are the substituents mentioned for the alkyl groups.Examples of suitable heterocycloalkyl groups, which may be unsubstitutedor substituted by the radicals mentioned above for the alkyl groups, areradicals derived from the following heterocycles: pyrrolidine, thiolane,tetrahydrofuran, 1,2-oxathiolane, oxazolidine, piperidine, thiane,oxane, dioxane, 1,3-dithiane, morpholine, piperazine. They may also bepolycyclic ring systems.

Suitable alkoxy radicals and alkylthio radicals derive correspondinglyfrom the aforementioned alkyl radicals. Examples here include OCH₃,OC₂H₅, OC₃H₇, OC₄H₉ and OC₈H₁₇, and also SCH₃, SC₂H₅, SC₃H₇, SC₄H₉ andSC₈H₁₇. In this context, C₃H₇, C₄H₉ and C₈H₁₇ comprise both then-isomers and branched isomers such as isopropyl, isobutyl, sec-butyl,tert-butyl and 2-ethylhexyl. Particularly preferred alkoxy or alkylthiogroups are methoxy, ethoxy, n-octyloxy, 2-ethylhexyloxy and SCH₃.

Suitable halogen radicals or halogen substituents in the context of thepresent application are fluorine, chlorine, bromine and iodine,preferably fluorine, chlorine and bromine, more preferably fluorine andchlorine, most preferably fluorine.

In the context of the present application, groups with donor or acceptoraction are understood to mean the following groups:

C₁-C₂₀-alkoxy, C₆-C₃₀-aryloxy, C₁-C₂₀-alkylthio, C₆-C₃₀-arylthio,SiR¹⁰R¹¹R¹², halogen radicals, halogenated C₁-C₂₀-alkyl radicals,carbonyl (—CO(R³²)), carbonylthio (—C═O(SR³²)), carbonyloxy(—C═O(OR³²)), oxycarbonyl (—OC═O(R³²)), thiocarbonyl (—SC═O(R³²)), amino(—NR³²R³³), OH, pseudohalogen radicals, amido (—C═O(NR³²R³³)),—NR³²C═O(R³³), phosphonate (—P(O)(OR³²)₂, phosphate (—OP(O)(OR³²)₂),phosphine (—PR³²R³³), phosphine oxide (—P(O)R³² ₂), sulfate(—OS(O)₂OR³²), sulfoxide (—S(O)R³²), sulfonate (—S(O)₂OR³²), sulfonyl(—S(O)₂R³²), sulfonamide (—S(O)₂NR³²R³³), NO₂, boronic esters(—OB(OR³²)₂), imino (—C═NR³²R³³)), borane radicals, stannate radicals,hydrazine radicals, hydrazone radicals, oxime radicals, nitroso groups,diazo groups, vinyl groups, sulfoximines, alanes, germanes, boroxinesand borazines.

Preferred substituents with donor or acceptor action are selected fromthe group consisting of: C₁- to C₂₀-alkoxy, preferably C₁-C₆-alkoxy,more preferably ethoxy or methoxy; C₆-C₃₀-aryloxy, preferablyC₆-C₁₀-aryloxy, more preferably phenyloxy; SiR¹⁰R¹¹R¹²; halogenradicals, preferably F, Cl, Br, more preferably F or Cl, most preferablyF, halogenated C₁-C₂₀-alkyl radicals, preferably halogenated C₁-C₆-alkylradicals, most preferably fluorinated C₁-C₆-alkyl radicals, e.g. CF₃,CH₂F, CHF₂ or C₂F₅; amino, preferably dimethylamino, diethylamino ordiphenylamino; OH, pseudohalogen radicals, preferably CN, SCN or OCN,more preferably CN, —C(O)OC₁-C₄-alkyl, preferably —C(O)OMe, P(O)R₂,preferably P(O)Ph₂, and SO₂R₂, preferably SO₂Ph.

Very particularly preferred substituents with donor or acceptor actionare selected from the group consisting of methoxy, phenyloxy,halogenated C₁-C₄-alkyl, preferably CF₃, CH₂F, CHF₂, C₂F₅, halogen,preferably F, CN, SiR¹⁰R¹¹R¹², where suitable R¹⁰, R¹¹ and R¹² radicalsare specified below, diphenylamino, or —C(O)OC₁-C₄-alkyl. Even morepreferred are OPh, halogen radicals, preferably F or Cl, more preferablyF; CF₃, CN; or SiR¹⁰R¹¹R¹², preferably SiMe₃, SiPh₃, SiEt₃ or SiPh₂tBu.

The aforementioned groups with donor or acceptor action are not intendedto rule out the possibility that further radicals and groups among thosespecified above may also have donor or acceptor action. For example, theaforementioned heteroaryl radicals are likewise groups with donor oracceptor action, and the C₁-C₂₀-alkyl radicals are groups with donoraction.

The R³² and R³³ radicals mentioned are each independently:

Hydrogen, substituted or unsubstituted C₁-C₂₀-alkyl or substituted orunsubstituted C₆-C₃₀-aryl or substituted or unsubstituted heteroarylhaving 5 to 30 ring atoms, suitable and preferred alkyl and arylradicals having been specified above. More preferably, the R³², R³³ andR³⁴ radicals are C₁-C₆-alkyl, e.g. methyl, ethyl, i-propyl ortert-butyl, or phenyl or pyridyl, most preferably methyl or phenyl.

The R¹⁰, R¹¹ and R¹² radicals mentioned are each independently:

a linear or branched alkyl radical, having from 1 to 6 carbon atoms,preferably methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl,sec-butyl or iso-butyl; a substituted or unsubstituted aryl radical,having from 6 to 18 carbon atoms, preferably phenyl or tolyl; asubstituted or unsubstituted heteroaryl radical, having a total of from5 to 18 carbon atoms and/or heteroatoms; a substituted or unsubstitutedcycloalkyl radical having a total of from 3 to 18 carbon atoms,preferably cyclopentyl or cyclohexyl.

Cyclometallated Ir Complex of Formula (I)

The metal in the cyclometallated Ir complex of formula (I) is preferablyIr(III).

The radicals, groups and symbols in the bidentate ligands of formula (I)of the cyclometallated Ir complex preferably have—independently of eachother—the following meanings:

R¹, R², R³, R⁴, R⁶ and R⁷

are each independently hydrogen; deuterium; a linear or branched,substituted or unsubstituted alkyl radical having from 1 to 20 carbonatoms, optionally interrupted by at least one heteroatom, selected fromO, S and N; a substituted or unsubstituted cycloalkyl radical having atotal of from 3 to 30 carbon atoms; a substituted or unsubstitutedheterocyclo alkyl radical, interrupted by at least one heteroatomselected from O, S and N and having a total of from 3 to 30 carbon atomsand/or heteroatoms; a substituted or unsubstituted aryl radical, havinga total of from 6 to 30 carbon atoms; a substituted or unsubstitutedheteroaryl radical, having a total of from 5 to 30 carbon atoms and/orheteroatoms, selected from O, S and N; or a group with donor or acceptoraction;

preferably, R¹, R², R³, R⁴, R⁶ and R⁷ are each independently hydrogen,deuterium, a linear or branched, substituted or unsubstituted alkylradical, having from 1 to 6 carbon atoms; a substituted or unsubstitutedcycloalkyl radical having a total of from 3 to 12 carbon atoms; anunsubstituted aryl radical, having from 6 to 12 carbon atoms, amonosubstituted aryl radical having from 6 to 18 carbon atoms, adisubstituted aryl radical having from 6 to 18 carbon atoms; anunsubstituted heteroaryl radical, having a total of from 5 to 16 carbonatoms and/or heteroatoms, a monosubstituted heteroaryl radical, having atotal of from 5 to 18 carbon atoms and/or heteroatoms, a disubstitutedheteroaryl radical, having a total of from 5 to 20 carbon atoms and/orheteroatoms; more preferably, the aryl radical or heteroaryl radical areselected from the group consisting of phenyl, pyridyl, pyrimidyl,pyrazinyl, carbazolyl, dibenzofuranyl, dibenzothiophenyl, fluorenyl,indolyl, benzofuranyl and benzothiophenyl wherein the aforementionedradicals may be unsubstituted or substituted by methyl, ethyl, n-propyl,iso-propyl, n-butyl, tert-butyl, sec-butyl, iso-butyl, cyclopentyl,cyclohexyl, methoxy, phenyl or CF₃; a group with donor or acceptoraction, selected from OPh, halogen radicals, preferably F or Cl, morepreferably F; CF₃, CN; or SiR¹⁰R¹¹R¹², preferably SiMe₃, SiPh₃, SiEt₃ orSiPh₂tBu;

or

R¹ and R², R³ and R⁴ and/or R⁶ and R⁷ may form, independently of eachother, together with the carbon atoms to which they are bonded, asaturated or unsaturated or aromatic, optionally substituted ring, whichis optionally interrupted by at least one heteroatom, selected from O, Sand N, has a total of from 5 to 18 carbon atoms and/or heteroatoms, andmay optionally be fused to at least one further optionally substitutedsaturated or unsaturated or aromatic ring, optionally interrupted by atleast one heteroatom, selected from O, S and N, and having a total offrom 5 to 18 carbon atoms and/or heteroatoms.

More preferably, R¹, R², R³, R⁴, R⁶ and R⁷ are each independentlyhydrogen; deuterium; methyl, ethyl, n-propyl, iso-propyl, n-butyl,tert-butyl, sec-butyl, iso-butyl, cyclopentyl, cyclohexyl, OCH₃, OCF₃;phenyl, pyridyl, pyrimidyl, pyrazinyl, carbazolyl, dibenzofuranyl,dibenzothiophenyl, benzofuranyl and benzothiophenyl wherein theaforementioned radicals may be unsubstituted or substituted by methyl,ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl, sec-butyl, iso-butyl,methoxy, CF₃ or phenyl; a group with donor or acceptor action, selectedfrom F, CF₃, CN and SiPh₃; most preferably, R¹, R², R³, R⁴, R⁶ and R⁷are each independently hydrogen; deuterium; methyl, ethyl, n-propyl,iso-propyl, n-butyl, tert-butyl, sec-butyl, iso-butyl; phenyl, pyridyl,pyrimidyl, pyrazinyl, carbazolyl, dibenzofuranyl, dibenzothiophenyl,wherein the aforementioned radicals may be unsubstituted or substitutedby methyl, ethyl, iso-propyl, tert-butyl, iso-butyl or methoxy; CF₃ orCN.

R¹⁰, R¹¹, R¹²

are each independently a linear or branched alkyl radical, having from 1to 6 carbon atoms, preferably methyl, ethyl, n-propyl, iso-propyl,n-butyl, tert-butyl, sec-butyl or iso-butyl; a substituted orunsubstituted aryl radical, having from 6 to 12 carbon atoms, preferablyphenyl or tolyl; a substituted or unsubstituted heteroaryl radical,having a total of from 5 to 15 carbon atoms and/or heteroatoms; asubstituted or unsubstituted cycloalkyl radical having a total of from 3to 7 carbon atoms, preferably cyclopentyl or cyclohexyl.

R⁵

is a linear or branched, substituted or unsubstituted alkyl radicalhaving from 1 to 20 carbon atoms, optionally interrupted by at least oneheteroatom, selected from O, S and N; a substituted or unsubstitutedcycloalkyl radical having a total of from 3 to 30 carbon atoms; asubstituted or unsubstituted heterocyclo alkyl radical, interrupted byat least one heteroatom selected from O, S and N and having a total offrom 3 to 30 carbon atoms and/or heteroatoms; a substituted orunsubstituted aryl radical, having a total of from 6 to 30 carbon atoms;a substituted or unsubstituted heteroaryl radical, having a total offrom 5 to 30 carbon atoms and/or heteroatoms, selected from O, S and N;or a group with donor or acceptor action;

preferably, R⁵ is a linear or branched, substituted or unsubstitutedalkyl radical, having from 1 to 6 carbon atoms; a substituted orunsubstituted cycloalkyl radical having a total of from 3 to 12 carbonatoms; an unsubstituted aryl radical, having from 6 to 12 carbon atoms,a monosubstituted aryl radical having from 6 to 18 carbon atoms, adisubstituted aryl radical having from 6 to 18 carbon atoms; anunsubstituted heteroaryl radical, having a total of from 5 to 16 carbonatoms and/or heteroatoms, a monosubstituted heteroaryl radical, having atotal of from 5 to 18 carbon atoms and/or heteroatoms, a disubstitutedheteroaryl radical, having a total of from 5 to 20 carbon atoms and/orheteroatoms; more preferably, the aryl radical or heteroaryl radical areselected from the group consisting of phenyl, pyridyl, pyrimidyl,pyrazinyl, carbazolyl, dibenzofuranyl, dibenzothiophenyl, benzofuranyland benzothiophenyl wherein the aforementioned radicals may beunsubstituted or substituted by methyl, ethyl, n-propyl, iso-propyl,n-butyl, tert-butyl, sec-butyl, iso-butyl, cyclopentyl, cyclohexyl,methoxy, phenyl, CF₃ or CN; a group with donor or acceptor action,selected from CF₃, CN; or SiR¹⁰R¹¹R¹², preferably SiMe₃, SiPh₃, SiEt₃ orSiPh₂tBu.

More preferably, R⁵ is methyl, ethyl, n-propyl, iso-propyl, n-butyl,tert-butyl, sec-butyl, iso-butyl, cyclopentyl, cyclohexyl, OCH₃, OCF₃;phenyl, pyridyl, pyrimidyl, pyrazinyl, wherein the aforementionedradicals may be substituted by, preferably monosubstituted by methyl,ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl, sec-butyl, iso-butyl,methoxy or phenyl or unsubstituted; a group with donor or acceptoraction, selected from CF₃ and CN;

most preferably, R⁵ is methyl, ethyl, n-propyl, iso-propyl, n-butyl,sec-butyl, iso-butyl; phenyl, tolyl or pyridyl.

Particularly preferred are complexes of formula (I), wherein:

R¹, R², R³, R⁴, R⁶ and R⁷

are each independently hydrogen; deuterium; methyl, ethyl, n-propyl,iso-propyl, n-butyl, tert-butyl, sec-butyl, iso-butyl, cyclopentyl,cyclohexyl, OCH₃, OCF₃; phenyl, pyridyl, pyrimidyl, pyrazinyl,carbazolyl, dibenzofuranyl, dibenzothiophenyl, benzofuranyl andbenzothiophenyl wherein the aforementioned radicals may be unsubstitutedor substituted by methyl, ethyl, n-propyl, iso-propyl, n-butyl,tert-butyl, sec-butyl, iso-butyl, methoxy, CF₃ or phenyl; a group withdonor or acceptor action, selected from F, CF₃, CN and SiPh₃; and

R⁵

is methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl, sec-butyl,iso-butyl, cyclopentyl, cyclohexyl, OCH₃, OCF₃; phenyl, pyridyl,pyrimidyl, pyrazinyl, wherein the aforementioned radicals may besubstituted by, preferably monosubstituted by methyl, ethyl, n-propyl,iso-propyl, n-butyl, tert-butyl, sec-butyl, iso-butyl, methoxy or phenylunsubstituted; a group with donor or acceptor action, selected from CF₃and CN.

Even more preferred are complexes of formula (I), wherein:

R¹, R², R³, R⁴, R⁶ and R⁷

are each independently hydrogen; deuterium; methyl, ethyl, n-propyl,iso-propyl, n-butyl, tert-butyl, sec-butyl, iso-butyl; phenyl, pyridyl,pyrimidyl, pyrazinyl, carbazolyl, dibenzofuranyl, dibenzothiophenyl,wherein the aforementioned radicals may be unsubstituted or substitutedby methyl, ethyl, iso-propyl, tert-butyl, iso-butyl or methoxy; CF₃ orCN; and

R⁵

is methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl;phenyl, tolyl or pyridyl.

X is CH, CD or N, preferably CH or N;

Y is CR⁸ or N, preferably CH or N.

Preferably, X and Y are each independently CH, CD or N, preferably CH orN.

In one preferred embodiment of the present invention

X is N; and

Y is CR⁸, preferably CH.

In a further preferred embodiment of the present invention

X is N; and

Y is N.

In a further preferred embodiment of the present invention

X is CH or CD, preferably CH; and

Y is CR⁸, preferably CH.

In a further embodiment of the present invention

X is CH or CD, preferably CH; and

Y is N.

R⁸

is hydrogen; deuterium; a linear or branched, substituted orunsubstituted alkyl radical having from 1 to 20 carbon atoms, optionallyinterrupted by at least one heteroatom, selected from O, S and N; asubstituted or unsubstituted cycloalkyl radical having a total of from 3to 30 carbon atoms; a substituted or unsubstituted heterocyclo alkylradical, interrupted by at least one heteroatom selected from O, S and Nand having a total of from 3 to 30 carbon atoms and/or heteroatoms; asubstituted or unsubstituted aryl radical, having a total of from 6 to30 carbon atoms; a substituted or unsubstituted heteroaryl radical,having a total of from 5 to 30 carbon atoms and/or heteroatoms, selectedfrom O, S and N; or a group with donor or acceptor action; preferably,R⁸ is hydrogen, deuterium, a linear or branched, substituted orunsubstituted alkyl radical, having from 1 to 6 carbon atoms; asubstituted or unsubstituted cycloalkyl radical having a total of from 3to 12 carbon atoms; an unsubstituted aryl radical, having from 6 to 12carbon atoms, a monosubstituted aryl radical having from 6 to 18 carbonatoms, a disubstituted aryl radical having from 6 to 18 carbon atoms; anunsubstituted heteroaryl radical, having a total of from 5 to 16 carbonatoms and/or heteroatoms, a monosubstituted heteroaryl radical, having atotal of from 5 to 18 carbon atoms and/or heteroatoms, a disubstitutedheteroaryl radical, having a total of from 5 to 20 carbon atoms and/orheteroatoms; more preferably, the aryl radical or heteroaryl radical areselected from the group consisting of phenyl, pyridyl, pyrimidyl,pyrazinyl, carbazolyl, dibenzofuranyl, dibenzothiophenyl, fluorenyl,indolyl, benzofuranyl and benzothiophenyl wherein the aforementionedradicals may be unsubstituted or substituted by methyl, ethyl, n-propyl,iso-propyl, n-butyl, tert-butyl, sec-butyl, iso-butyl, cyclopentyl,cyclohexyl, methoxy, phenyl, CF₃ or CN; a group with donor or acceptoraction, selected from halogen radicals, preferably F or Cl, morepreferably F; CF₃, CN; or SiR¹⁰R¹¹R¹², preferably SiMe₃, SiPh₃, SiEt₃ orSiPh₂tBu.

The carbene ligands in the cyclometallated Ir complexes of formula (I)are monoanionic bidentate ligands.

Preferably, the three carbene ligands in the cyclometallated Ircomplexes of the general formula (I) are identical.

In a preferred embodiment of the present invention, the cyclometallatedIr complexes of formula (I) are meridional (mer) complexes.

Preferred cyclometallated Ir complexes of formula (I) are:

Compounds of formula (I)

wherein the radicals and groups R¹, R², R³, R⁴, R⁶, R⁵, R⁷, X and Y havethe following meanings:

Cpd. X Y R⁷ R⁶ R⁵ R⁴ R³ R² R¹  1 N N H H methyl H H H H  2 N CH H Hmethyl H H H H  3 CH CH H H methyl H H H H  4 CH N H H methyl H H H H  5N CH H H methyl CN H H tert-butyl  6 N N H H methyl CN H H tert-butyl  7CH CH H H Methyl CN H H tert-butyl  8 CH N H H Methyl CN H H tert-butyl 9 N CH H H Methyl CF₃ H H H  10 N N H H methyl CF₃ H H H  11 CH CH H Hmethyl CF₃ H H H  12 CH N H H methyl CF₃ H H H  13 N N H H methyl Ho-tolyl H H  14 N CH H H methyl H o-tolyl H H  15 CH CH H H methyl Ho-tolyl H H  16 CH N H H methyl H o-tolyl H H  17 N N H H phenyl H H H H 18 N CH H H phenyl H H H H  19 CH CH H H phenyl H H H H  20 CH N H Hphenyl H H H H  21 N N Phenyl H methyl H H H H  22 N CH Phenyl H methylH H H H  23 CH CH phenyl H methyl H H H H  24 CH N phenyl H methyl H H HH  25 N N H H —CH₃ H H H H  26 N N H H —CH₂CH₃ H H H H  27 N N H Hiso-propyl H H H H  28 N N H H —CH₃ H H H iso-butyl  29 N N H H —Ph H HH iso-butyl  30 N N H H neopentyl H H H H  31 N N H H

H H H H  32 N N H H

H H H H  33 N N H H —CH₃ H H H tert-butyl  34 N N H H —Ph H H Htert-butyl  35 N N H

—CH₃ H H H H  36 N N H

—CH₃ H H H H  37 N N H H H H H H   N N H H —CH₃ H H H

 38 N N H H —CH₃ H H H

 39 N N H H —CH₃ H H H

 40 N N H H —CH₃ H H H

 41 N N H H —CH₃ H H H

 42 N N H H —CH₃ H H H

 43 N N H H —Ph H H H

 44 N N H H —Ph H H H

 45 N N H H —Ph H H H

 46 N N H H —Ph H H H

 47 N N H H ——Ph H H H

 48 N N H H —Ph H H H

 49 N CH H H —CH₃ H H H H  50 N CH H H —CH₂CH₃ H H H H  51 N CH H Hiso-propyl H H H H  52 N CH H H —CH₃ H H H iso-butyl  53 N CH H H —Ph HH H iso-butyl  54 N CH H H neopentyl H H H H  55 N CH H H

H H H H  56 N CH H H

H H H H  57 N CH H H —CH₃ H H H tert-butyl  58 N CH H H —Ph H H Htert-butyl  59 N CH H

—CH₃ H H H H  60 N CH H

—CH₃ H H H H  61 N CH H H —CH₃ H H H

 62 N CH H H —CH₃ H H H

 63 N CH H H —CH₃ H H H

 64 N CH H H —CH₃ H H H

 65 N CH H H —CH₃ H H H

 66 N CH H H —CH₃ H H H

 67 N CH H H —Ph H H H

 68 N CH H H —Ph H H H

 69 N CH H H —Ph H H H

 70 N CH H H —Ph H H H

 71 N CH H H —Ph H H H

 72 N CH H H —Ph H H H

 73 CH N H H —CH₃ H H H H  74 CH N H H —CH₂CH₃ H H H H  75 CH N H Hiso-propyl H H H H  76 CH N H H —CH₃ H H H iso-butyl  77 CH N H H —Ph HH H iso-butyl  78 CH N H H neopentyl H H H H  79 CH N H H

H H H H  80 CH N H H

H H H H  81 CH N H H —CH₃ H H H tert-butyl  82 CH N H H —Ph H H Htert-butyl  83 CH N H

—CH₃ H H H H  84 CH N H

—CH₃ H H H H  85 CH N H H —CH₃ H H H

 86 CH N H H —CH₃ H H H

 87 CH N H H —CH₃ H H H

 88 CH N H H —CH₃ H H H

 89 CH N H H —CH₃ H H H

 90 CH N H H —CH₃ H H H

 91 CH N H H —Ph H H H

 92 CH N H H —Ph H H H

 93 CH N H H —Ph H H H

 94 CH N H H —Ph H H H

 95 CH N H H —Ph H H H

 96 CH N H H —Ph H H H

 97 CH CH H H —CH₃ H H H H  98 CH CH H H —CH₂CH₃ H H H H  99 CH CH H Hiso-propyl H H H H 100 CH CH H H —CH₃ H H H iso-butyl 101 CH CH H H —PhH H H iso-butyl 102 CH CH H H neopentyl H H H H 103 CH CH H H

H H H H 104 CH CH H H

H H H H 105 CH CH H H —CH₃ H H H tert-butyl 106 CH CH H H —Ph H H Htert-butyl 107 CH CH H

—CH₃ H H H H 108 CH CH H

—CH₃ H H H H 109 CH CH H H —CH₃ H H H

110 CH CH H H —CH₃ H H H

111 CH CH H H —CH₃ H H H

112 CH CH H H —CH₃ H H H

113 CH CH H H —CH₃ H H H

114 CH CH H H —CH₃ H H H

115 CH CH H H —Ph H H H

116 CH CH H H —Ph H H H

117 CH CH H H —Ph H H H

118 CH CH H H —Ph H H H

119 CH CH H H —Ph H H H

120 CH CH H H —Ph H H H

Particularly preferred inventive cyclometallated Ir complexes of formula(I) are the following complexes:

Most preferred inventive cyclometallated Ir complexes of formula (I) arethe following complexes:

The present invention also relates to a process for preparing theinventive cyclometallated Ir complexes of formula (I) by contactingsuitable compounds comprising Ir with the appropriate ligands or ligandprecursors.

In one embodiment of the process according to the invention, a suitablecompound comprising iridium and appropriate carbene ligands, preferablyin deprotonated form as the free carbene or in the form of a protectedcarbene, for example as the silver-carbene complex, are contacted.

The present invention therefore relates—in one embodiment—to a processaccording to the invention wherein the ligand precursor used is acorresponding Ag-carbene complex.

In a further preferred embodiment of the process according to theinvention, the ligand precursors used are organic compounds which arereacted with suitable Ir comprising compounds. The carbene can bereleased from precursors of the carbene ligands by removing volatilesubstances, for example lower alcohols such as methanol or ethanol, forexample at elevated temperature and/or under reduced pressure and/orusing molecular sieves which bind the alcohol molecules eliminated.Corresponding processes are known to those skilled in the art.

The present invention also relates to the process according to theinvention wherein the ligand precursor used is a compound of the generalformula (IV)

wherein A¹, A², A³, R³, R⁴, R⁶, R⁵, R⁷, X and Y are each as alreadydefined above for the compounds of the general formula (I), and R¹³ isdefined as follows:

R¹³ is independently SiR¹⁴R¹⁵R¹⁶, aryl, heteroaryl, alkyl, cycloalkyl orheterocycloalkyl,

R¹⁴, R¹⁵,

R¹⁶ are each independently aryl, heteroaryl, alkyl, cycloalkyl orheterocycloalkyl.

The definitions of aryl, heteroaryl, alkyl, cycloalkyl andheterocycloalkyl have been specified above.

In a particularly preferred embodiment, R¹³ is alkyl, especiallyC₁-C₂₀-alkyl, preferably C₁-C₁₀-alkyl, more preferably C₁-C₈-alkyl, forexample methyl, ethyl, propyl such as n-propyl, iso-propyl, butyl suchas n-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl or octyl.

R¹³ in the compound of the general formula (IV) is most preferablymethyl or ethyl.

Compounds of the general formula (IV) are generally obtainable byprocesses known to those skilled in the art. Compounds of the generalformula (IV) can be obtained for example by reacting compounds of thegeneral formula (Va)

or the corresponding Cl or BF₄ salt of formula (Vb)

wherein X⁻ is Cl⁻ or BF₄ ⁻,

with compounds of the general formula (VI)HC(OR¹³)₃  (VI),

or

by reacting compounds of the general formula (Va) or (Vb) in a firststep with Vilsmeier reagent ((chloromethylene)dimethylammonium chloride)and a sodium salt selected from NaBF₄, NaCl, NaBr or NaI to obtain acompound of formula (Vc)

wherein X⁻ is BF₄ ⁻, Cl⁻, Br⁻ or I⁻ and

in a second step with R¹³OH or M″OR¹³, wherein M″ is an alkali metalsalt, preferably Na,

and

where A¹, A², A³, R³, R⁴, R⁶, R⁵, R⁷, X, Y and R¹³ are each as alreadydefined above for the compounds of the general formula (IV) or for thecyclometallated Ir complexes of formula (I).

This preparation of the compounds of the general formula (IV) can beeffected in the presence or in the absence of a solvent. Suitablesolvents are specified below. In one preferred embodiment, the compoundsof the general formula (IV) are prepared in substance, or the compoundof the general formula (VI) is added in an excess, such that itfunctions as a solvent.

Compounds of the general formulae (Va), (Vb), (Vc) and (VI) arecommercially available and/or obtainable by processes known to thoseskilled in the art; for example, compounds of the general formula (Va),(Vb), (Vc) are obtainable by reacting the appropriate chlorides with theappropriate amines.

The compounds of the general formula (IV) are prepared generally at atemperature of 10 to 150° C., preferably 40 to 120° C., more preferably60 to 110° C.

The reaction time is generally 2 to 48 hours, preferably 6 to 24 hours,more preferably 8 to 16 hours.

After the reaction has ended, the desired product can be isolated andpurified by customary processes known to those skilled in the art, forexample filtration, recrystallization, column chromatography, etc.

Appropriate compounds, especially complexes comprising iridium, areknown to those skilled in the art. Particularly suitable compoundscomprising iridium comprise, for example, ligands such as halides,preferably chloride, 1,5-cyclooctadiene (COD), cyclooctene (COE),phosphines, cyanides, alkoxides, pseudohalides and/or alkyl.

Particularly preferred complexes comprising iridium are selected fromthe group consisting of [Ir(COD)Cl]₂, [Ir(COE)₂Cl]₂IrCl₃×H₂O, Ir(acac)₃,Ir(COD)₂BF₄, Ir(COD)₂BARF(BARF=tetrakis[3,5-bis(trifluoromethyl)phenyl]borate)) and mixturesthereof.

The carbene ligand precursors are deprotonated, preferably before thereaction, for example, by basic compounds known to those skilled in theart, for example basic metalates, basic metal acetates, acetylacetonatesor alkoxides, or bases such as KO^(t)Bu, NaO^(t)Bu, LiO^(t)Bu, NaH,silylamides, Ag₂O and phosphazene bases. Particular preference is givento deprotonating with Ag₂O to obtain the corresponding Ag-carbene, whichis reacted with the compound comprising M to give the inventivecomplexes.

Particularly preferably, the carbene can be released from precursors ofthe carbene ligands by removing volatile substances, for example loweralcohols.

The process according to the invention for preparing the cyclometallatedIr complexes of formula (I) according to the present invention using thecompounds of the general formula (IV) has the advantage that thecompounds of the general formula (IV) are stable intermediates which canbe handled readily and can be isolated under standard laboratoryconditions. In addition, the compounds of the general formula (IV) aresoluble in customary organic solvents, such that the preparation of theinventive cyclometallated Ir complexes of formula (I) in homogeneoussolution is possible, such that a workup of the desired product, i.e. ofthe cyclometallated Ir complexes of formula (I) is more readilypossible, for example for isolation and/or purification.

The contacting is preferably effected in a solvent. Suitable solventsare known per se to those skilled in the art and are preferably selectedfrom the group consisting of aromatic or aliphatic solvents, for examplebenzene, toluene, xylene or mesitylene, cyclic or acyclic ethers, forexample dioxane or THF, alcohols, esters, amides, ketones, nitriles,halogenated compounds and mixtures thereof. Particularly preferredsolvents are toluene, xylenes, mesitylene and dioxane.

The molar ratio of metal-noncarbene complex used to carbene ligandprecursor used is generally 1:10 to 10:1, preferably 1:1 to 1:6, morepreferably 1:3 to 1:5.

The contacting is generally effected at a temperature of 20 to 200° C.,preferably 50 to 150° C., more preferably 60 to 150° C.

The reaction time depends on the desired carbene complex and isgenerally 0.02 to 50 hours, preferably 0.1 to 24 hours, more preferably1 to 24 hours.

The cyclometallated Ir complexes of formula (I) obtained after thereaction can optionally be purified by processes known to those skilledin the art, for example washing, crystallization or chromatography.

The particular advantage of the process according to the presentinvention is the formation of only or mainly the mer isomer of thecyclometallated Ir complexes according to the present invention. This isdue to the fact that asymmetric diaryl substituted carbene ligandsbearing a substituent at the 2 position of one of the aryl residuesbound to one of the carbene nitrogen atoms are present in thecyclometallated Ir complexes and the corresponding compounds of formulae(IV), (Va), (Vb) or (Vc) are used in the preparation of thecyclometallated Ir complexes. It has surprisingly been found by theinventors of the present invention that it is now possible to isolatethe mer isomers of metal-carbene complexes having diaryl substitutedcarbene ligands as main products.

In the process of the present invention, the weight ratio of mer to facisomer of the cyclometallated Ir complexes of formula (I) is in general100%-50% (mer) to 0%-50% (fac), preferably, 100%-60% (mer) to 0%-40%(fac), more preferably 100%-75% (mer) to 0%-25% (fac).

It should be considered that it is in general not possible to convertthe thermodynamically preferred fac isomer of cyclometallated Ir carbenecomplexes back into the mer isomer.

A further advantage of the process according to the present invention isthe formation of only one or mainly one cyclometallation isomer of thecyclometallated Ir complexes according to the present invention. This isalso due to the fact that asymmetric diaryl substituted carbene ligandsbearing a substituent at the 2 position of one of the aryl residuesbound to one of the carbene nitrogen atoms are present in thecyclometallated Ir complexes and the corresponding compounds of formulae(IV), (Va), (Vb) or (Vc) are used in the preparation of thecyclometallated Ir complexes. Since only one or mainly onecyclometallation isomer is present, the separation of the isomers whichis usually accompanied by a loss of material associated with low yieldsis not necessary.

In a further embodiment, the present invention relates to an organicelectronic device comprising at least one cyclometallated Ir complexaccording to the present invention.

Structures of the Organic Electronic Devices

Suitable structures of the organic electronic devices are known to thoseskilled in the art. Preferred organic electronic devices are selectedfrom organic light-emitting diodes (OLED), light-emittingelectrochemical cells (LEEC), organic photovoltaic cells (OPV) andorganic field-effect transistors (OFET). More preferred organicelectronic devices are OLEDs.

The organic light-emitting diode (OLED) is usually a light-emittingdiode (LED) in which the emissive electroluminescent layer is a film oforganic compound which emits light in response to an electric current.This layer of organic semiconductor is usually situated between twoelectrodes. Generally, at least one of these electrodes is transparent.The cyclometallated Ir complex of formula (I) may be present in anydesired layer, preferably in the emissive electroluminescent layer(light-emitting layer), of the OLED as emitter material.

The light-emitting electrochemical cell (LEEC) is usually a solid-statedevice that generates light from an electric current(electroluminescence). LEEC's are usually composed of two metalelectrodes connected by (e.g. sandwiching) an organic semiconductorcontaining mobile ions. Aside from the mobile ions, their structure isvery similar to that of an organic light-emitting diode (OLED). Thecyclometallated Ir complex of formula (I) may be present in any desiredlayer as emitter material.

The organic field-effect transistor (OFET) generally includes asemiconductor layer formed from an organic layer with hole transportcapacity and/or electron transport capacity; a gate electrode formedfrom a conductive layer; and an insulation layer introduced between thesemiconductor layer and the conductive layer. A source electrode and adrain electrode are mounted on this arrangement in order thus to producethe transistor element. In addition, further layers known to thoseskilled in the art may be present in the organic transistor. Thecyclometallated Ir complex of formula (I) may be present in any desiredlayer.

The organic photovoltaic cell (OPV) (photoelectric conversion element)generally comprises an organic layer present between two plate-typeelectrodes arranged in parallel. The organic layer may be configured ona comb-type electrode. There is no particular restriction regarding thesite of the organic layer and there is no particular restrictionregarding the material of the electrodes. When, however, plate-typeelectrodes arranged in parallel are used, at least one electrode ispreferably formed from a transparent electrode, for example an ITOelectrode or a fluorine-doped tin oxide electrode. The organic layer isusually formed from two sublayers, i.e. a layer with p-typesemiconductor character or hole transport capacity, and a layer formedwith n-type semiconductor character or electron transport capacity. Inaddition, it is possible for further layers known to those skilled inthe art to be present in the organic solar cell. The cyclometallated Ircomplex of formula (I) may be present in any desired layer, of the OPV,preferably as absorption dye.

The organic electronic device is most preferably an OLED or LEEC or OPV,wherein the cyclometallated Ir complex of formula (I) is preferablyemployed in the light-emitting layer and or hole transport layer, morepreferably as emitter material in OLEDs or LEECs, preferably OLEDs, oras absorption dye in OPVs. The organic electronic device is mostpreferably an OLED, wherein the cyclometallated Ir complex of formula(I) is employed in the light-emitting layer and/or hole transport layer.Even more preferably, the metal-carbene complex of formula (I) isemployed as emitter material.

The present invention therefore preferably relates to an organicelectronic device which is an OLED, wherein the OLED comprises

(a) an anode,

(b) a cathode,

(c) a light-emitting layer between the anode and the cathode,

(d) optionally a hole transport layer between the light-emitting layerand the anode,

wherein the cyclometallated Ir complex of formula (I) is present in thelight-emitting layer and/or—if present—in the hole transport layer ofthe OLED.

The structure of the inventive OLED will be described in detail below.

Cyclometallated Ir Complex of Formula (I) as Emitter Material

According to the present invention, the cyclometallated Ir complexes offormula (I) are employed in an organic electronic device, preferably inan OLED. More preferably, the cyclometallated Ir complexes of formula(I) are employed as emitter material, preferably as emitter material inthe light-emitting layer of an OLED. Suitable OLEDs are known in the artand the preferred structures of suitable OLEDs are described aboveand—in more detail—below.

The cyclometallated Ir complexes of formula (I) are preferablyphosphorescence emitter showing emission of light by phosphorescence.However, this does not exclude that the phosphorescence emitteradditionally shows emission of light by fluorescence.

The phosphorescence emitter show phosphorescence emission from tripletexcited states, preferably at the operating temperatures of the OLED.Generally, the operating temperatures of the OLED are −40 to +90° C.Phosphorescence may be preceded by a transition from a triplet excitedstate to an intermediate non-triplet state from which the emissive decayoccurs.

The emission decay time (intensity reduced to 1/e=0.367879441 times itsinitial value) τ₀ of the luminescence emission of the cyclometallated Ircomplex of formula (I) is preferably of from 0.1 to 20 micro seconds,more preferably of from 0.1 to 10 micro seconds, most preferably of from0.1 to 4 micro seconds.

The mer complexes of the present invention are characterized by veryshort emission decay times compared with the corresponding fac isomers.The emission decay time of the mer complexes τ₀ is in many cases half aslong as the emission decay time of the corresponding fac complexes.

The emission decay time of the complexes of formula (I), wherein X is N;and Y is CR⁸, preferably CH, or N is in a particularly preferredembodiment 0.1 to 2 micro seconds, even more preferably 0.1 to 1.5 microseconds.

Further Emitter Materials

The cyclometallated Ir complex of formula (I) may be employed alone asthe only emitter material or in a mixture with one or morecyclometallated Ir complexes of formula (I) and/or one or more furtheremitter materials, preferably in the light-emitting layer of an OLED.Suitable further emitter materials are known by a person skilled in theart.

Suitable Further Emitter Materials are for Example:

Phosphorescence emitter compounds based on metal complexes, andespecially the complexes of the metals Ru, Rh, Ir, Pd and Pt, inparticular the complexes of Ir

Suitable metal complexes for use in the inventive organic electronicdevice, preferably in the OLEDs, are described, for example, indocuments WO 02/60910 A1, US 2001/0015432 A1, US 2001/0019782 A1, US2002/0055014 A1, US 2002/0024293 A1, US 2002/0048689 A1, EP 1 191 612A2, EP 1 191 613 A2, EP 1 211 257 A2, US 2002/0094453 A1, WO 02/02714A2, WO 00/70655 A2, WO 01/41512 A1, WO 02/15645 A1, WO 2005/019373 A2,WO 2005/113704 A2, WO 2006/115301 A1, WO 2006/067074 A1, WO 2006/056418,WO 2006121811 A1, WO 2007095118 A2, WO 2007/115970, WO 2007/115981, WO2008/000727, WO 2010/086089, WO 2012/121936 A2, US 2011/0057559, WO2011/106344, US 2011/0233528 and WO 2011/157339, WO2008156879,WO2010068876, US20110233528, WO2012048266, WO2013031662, WO2013031794.

Further suitable metal complexes are the commercially available metalcomplexes tris(2-phenylpyridine)iridium(III), iridium(III)tris(2-(4-tolyl)pyridinato-N,C^(2′)),bis(2-phenylpyridine)(acetylacetonato)iridium(III), iridium(III)tris(1-phenylisoquinoline), iridium(III)bis(2,2′-benzothienyl)(pyridinato-N,C^(3′))(acetylacetonate),tris(2-phenylquinoline)iridium(III), iridium(III)bis(2-(4,6-difluorophenyl)pyridinato-N,C²)picolinate, iridium(III)bis(1-phenylisoquinoline)(acetylacetonate),bis(2-phenylquinoline)(acetylacetonato)iridium(III), iridium(III)bis(dibenzo[f,h]quinoxaline)(acetylacetonate), iridium(III)bis(2-methyldibenzo[f,h]quinoxaline)(acetylacetonate),bis[1-(9,9-dimethyl-9H-fluoren-2-yl)isoquinoline](acetylacetonato)iridium(III),bis(2-phenylbenzo-thiazolato)(acetylacetonato)iridium(III),bis(2-(9,9-dihexylfluorenyl)-1-pyridine)(acetyl-acetonato)iridium(III),bis(2-benzo[b]thiophen-2-ylpyridine)(acetylacetonato)iridium(III).

Preferred further phosphosphorescence emitters are carbene complexes.Carbene complexes which are suitable phosphorescent blue emitters arespecified in the following publications: WO 2006/056418 A2, WO2005/113704, WO 2007/115970, WO 2007/115981, WO 2008/000727,WO2009050281, WO2009050290, WO2011051404, US2011/057559 WO2011/073149,WO2012/121936A2, US2012/0305894A1, WO2012170571, WO2012170461, WO2012170463, WO2006121811, WO2007095118, WO2008156879, WO2008156879,WO2010068876, US20110057559, WO2011106344, US20110233528, WO2012048266and WO2012172482.

Preferably, the cyclometallated Ir complex of formula (I) is employedalone—as the only emitter material, preferably in the light-emittinglayer of an OLED.

Host Material

The cyclometallated Ir complex of formula (I) or the mixture of emittermaterials mentioned above may be employed, preferably in thelight-emitting layer of an OLED, without further additional componentsor with one or more further components in addition to the emittermaterial. For example, a fluorescent dye may be present in thelight-emitting layer of an OLED in order to alter the emission color ofthe emitter material. In addition—in a preferred embodiment—one or morehost (matrix) material can be used. This host material may be a polymer,for example poly(N-vinylcarbazole). The host material may, however,likewise be a small molecule, for example 4,4′-N,N′-dicarbazolebiphenyl(CDP=CBP) or tertiary aromatic amines, for example TCTA.

Suitable as host material are carbazole derivatives, for example4,4′-bis(carbazol-9-yl)-2,2′-dimethylbiphenyl (CDBP),4,4′-bis(carbazol-9-yl)biphenyl (CBP), 1,3-bis(N-carbazolyl)benzene(mCP), and the host materials specified in the following applications:WO2008/034758, WO2009/003919.

Further suitable host materials, which may be small molecules or(co)polymers of the small molecules mentioned, are specified in thefollowing publications: WO2007108459 (H-1 to H-37), preferably H-20 toH-22 and H-32 to H-37, most preferably H-20, H-32, H-36, H-37,WO2008035571 A1 (Host 1 to Host 6), JP2010135467 (compounds 1 to 46 andHost-1 to Host-39 and Host-43), WO2009008100 compounds No. 1 to No. 67,preferably No. 3, No. 4, No. 7 to No. 12, No. 55, No. 59, No. 63 to No.67, more preferably No. 4, No. 8 to No. 12, No. 55, No. 59, No. 64, No.65, and No. 67, WO2009008099 compounds No. 1 to No. 110, WO2008140114compounds 1-1 to 1-50, WO2008090912 compounds OC-7 to OC-36 and thepolymers of Mo-42 to Mo-51, JP2008084913 H-1 to H-70, WO2007077810compounds 1 to 44, preferably 1, 2, 4-6, 8, 19-22, 26, 28-30, 32, 36,39-44, WO201001830 the polymers of monomers 1-1 to 1-9, preferably of1-3, 1-7, and 1-9, WO2008029729 the (polymers of) compounds 1-1 to 1-36,WO20100443342 HS-1 to HS-101 and BH-1 to BH-17, preferably BH-1 toBH-17, JP2009182298 the (co)polymers based on the monomers 1 to 75,JP2009170764, JP2009135183 the (co)polymers based on the monomers 1-14,WO2009063757 preferably the (co)polymers based on the monomers 1-1 to1-26, WO2008146838 the compounds a-1 to a-43 and 1-1 to 1-46,JP2008207520 the (co)polymers based on the monomers 1-1 to 1-26,JP2008066569 the (co)polymers based on the monomers 1-1 to 1-16,WO2008029652 the (co)polymers based on the monomers 1-1 to 1-52,WO2007114244 the (co)polymers based on the monomers 1-1 to 1-18,JP2010040830 the compounds HA-1 to HA-20, HB-1 to HB-16, HC-1 to HC-23and the (co)polymers based on the monomers HD-1 to HD-12, JP2009021336,WO2010090077 the compounds 1 to 55, WO2010079678 the compounds H1 toH42, WO2010067746, WO2010044342 the compounds HS-1 to HS-101 and Poly-1to Poly-4, JP2010114180 the compounds PH-1 to PH-36, US2009284138 thecompounds 1 to 111 and H1 to H71, WO2008072596 the compounds 1 to 45,JP2010021336 the compounds H-1 to H-38, preferably H-1, WO2010004877 thecompounds H-1 to H-60, JP2009267255 the compounds 1-1 to 1-105,WO2009104488 the compounds 1-1 to 1-38, WO2009086028, US2009153034,US2009134784, WO2009084413 the compounds 2-1 to 2-56, JP2009114369 thecompounds 2-1 to 2-40, JP2009114370 the compounds 1 to 67, WO2009060742the compounds 2-1 to 2-56, WO2009060757 the compounds 1-1 to 1-76,WO2009060780 the compounds 1-1 to 1-70, WO2009060779 the compounds 1-1to 1-42, WO2008156105 the compounds 1 to 54, JP2009059767 the compounds1 to 20, JP2008074939 the compounds 1 to 256, JP2008021687 the compounds1 to 50, WO2007119816 the compounds 1 to 37, WO2010087222 the compoundsH-1 to H-31, WO2010095564 the compounds HOST-1 to HOST-61, WO2007108362,WO2009003898, WO2009003919, WO2010040777, US2007224446, WO06128800,WO2012014621, WO2012105310, WO2012/130709. European patent applicationsEP12175635.7 and EP12185230.5 and EP12191408.9 (in particular page 25 to29 of EP12191408.9), WO2012048266, WO2012145173, WO2012162325, andEP2551932.

In a particularly preferred embodiment, one or more compounds of thegeneral formula (IX) specified hereinafter are used as host material:

wherein

X′ is NR, S, O or PR;

R is aryl, heteroaryl, alkyl, cycloalkyl, or heterocycloalkyl;

A²⁰⁰ is —NR²⁰⁶R²⁰⁷, —P(O)R²⁰⁸R²⁰⁹, —PR²¹⁰R²¹¹, —S(O)₂R²¹², —S(O)R²¹³,—SR²¹⁴, or —OR²¹⁵;

R²²¹, R²²² and R²²³ are independently of each other aryl, heteroaryl,alkyl, cycloalkyl, or heterocycloalkyl, wherein at least on of thegroups R²²¹, R²²², or R²²³ is aryl, or heteroaryl;

R²⁰⁴ and R²⁰⁵ are independently of each other alkyl, cycloalkyl,heterocycloalkyl, aryl, heteroaryl, a group A²⁰⁰, or a group havingdonor, or acceptor characteristics;

n2 and m1 are independently of each other 0, 1, 2, or 3;

R²⁰⁶, R²⁰⁷ form together with the nitrogen atom a cyclic residue having3 to 10 ring atoms, which can be unsubstituted, or which can besubstituted with one, or more substituents selected from alkyl,cycloalkyl, heterocycloalkyl, aryl, heteroaryl and a group having donor,or acceptor characteristics; and/or which can be annulated with one, ormore further cyclic residues having 3 to 10 ring atoms, wherein theannulated residues can be unsubstituted, or can be substituted with one,or more substituents selected from alkyl, cycloalkyl, heterocycloalkyl,aryl, heteroaryl and a group having donor, or acceptor characteristics;and

R²⁰⁸, R²⁰⁹, R²¹⁰, R²¹¹, R²¹², R²¹³, R²¹⁴ und R²¹⁵ are independently ofeach other aryl, heteroaryl, alkyl, cycloalkyl, or heterocycloalkyl.

Compounds of formula (IX) and their preparation processes, such as, forexample,

are described in WO 2010/079051 A1 (in particular pages on 19 to 26 andin tables on pages 27 to 34, pages 35 to 37 and pages 42 to 43).

Additional host materials on basis of dibenzofurane are, for example,described in US 2009066226, EP1 885 818 B1, EP 1 970 976, EP 1 998 388and EP 2 034 538. Examples of particularly preferred host materials areshown below:

In the above-mentioned compounds T is O, or S, preferably O. If T occursmore than one time in a molecule, all groups T have the same meaning.

The more preferred host compounds are shown below:

as well as the host materials published in WO2012048266, WO2012145173,WO2012162325, and EP2551932.

The most preferred host compounds are shown below:

The present invention therefore also concerns the organic electronicdevice, preferably the OLED, according to the present invention, whereinthe at least one cyclometallated Ir complex of formula (I) is employedin combination with at least one host material. Suitable and preferredhost materials are mentioned above.

More preferably, the at least one host material comprises at least onedibenzofuranyl unit and/or at least one benzimidazo[1,2-a]benzimidazolylunit and/or at least one carbazolyl and/or at least onedibenzothiofuranyl unit. Suitable host materials and preferred hostmaterials comprising at least one dibenzofuranyl unit and/or at leastone benzimidazo[1,2-a]benzimidazolyl unit and/or at least one carbazolyland/or at least one dibenzothiofuranyl unit are mentioned above. The atleast one cyclometallated Ir complex of formula (I) which is employed incombination with at least one host material is preferably employed inthe light-emitting layer of an OLED.

Preferably, the light-emitting layer comprises at least one emittermaterial, which is a cyclometallated Ir complex of formula (I) accordingto the present invention, and at least one host material. Suitable andpreferred emitter materials as well as suitable and preferred hostmaterials are mentioned above.

Most preferably, the organic electronic device, preferably the OLED,comprises a light-emitting layer comprising at least one cyclometallatedIr complex of formula (I) as emitter material in an amount of 5 to 40%by weight, preferably 5 to 30% by weight, more preferably 5 to 20 byweight, and at least one host material or at least one host material andat least one co-host material as described below, wherein preferred hostmaterials are mentioned above and preferred co-hosts are mentionedbelow, in an amount of 60 to 95% by weight, preferably 70 to 95% byweight, more preferably 80 to 95% by weight (the amount is either theamount of the at least one host or the amount of the sum of the at leastone host and the at least one co-host—the ratio of at least one host toat least one co-host is given below), where the amount of the at leastone emitter material and the at least one host material or the at leastone host material and the at least one co-host, adds up to a total of100% by weight.

The light-emitting layer may comprise a second host compound (co-host).The second host compound can be one compound or it can be a mixture oftwo or more compounds. Ir carbene complexes, preferably the Ir carbenecomplexes Ir(DPBIC)₃, Ir(DPABIC)₃ or Ir(DPABIC)₂(DPBIC) which aredescribed below, may be added as second host.

(as described in WO 2005/019373A2)

(as described as complex Emi in WO2012/172182 (synthesis: example 1) andin the not yet published EP application EP 13162776.2)

(as described as complex Em10 in WO2012/172482 (synthesis: example 10)).

Mixed matrix materials with two hosts selected from those hostsmentioned above, or one host from those hosts mentioned above and oneco-host as described above, comprise preferably 5% by weight to 15% byweight of at least one, preferably one, co-host and 60% by weight to 90%by weight of a further host selected from the hosts as mentioned above.

The layer thickness of the light-emitting layer in the inventive OLED ispreferably from 1 to 100 nm, more preferably 5 to 60 nm. Preferred OLEDstructures are mentioned above and—in more detail—below.

Device Structure—OLED Structure

Suitable structures of the organic electronic devices are known to thoseskilled in the art. Preferred organic electronic devices are selectedfrom organic light-emitting diodes (OLED), light-emittingelectrochemical cells (LEEC), organic photovoltaic cells (OPV) andorganic field-effect transistors (OFET). More preferred organicelectronic devices are OLEDs.

The device structures of said OLEDs, LEECs, OPVs and OFETs have beendescribed above in general terms. In the following, the devicestructures of preferred OLEDs (which are preferred electronic devicesaccording to the present invention) are described.

As mentioned above, the present invention preferably relates to anorganic electronic device which is an OLED, wherein the OLED comprises

(a) an anode,

(b) a cathode,

(c) a light-emitting layer between the anode and the cathode,

(d) optionally a hole transport layer between the light-emitting layerand the anode,

wherein the cyclometallated Ir complex of formula (I) is present in thelight-emitting layer and/or—if present—in the hole transport layer ofthe OLED.

Preferred cyclometallated Ir complexes of formula (I) are mentionedbefore.

The layer sequence in the inventive OLED is preferably as follows:

1. anode (a)

2. hole-transport layer (d)

3. electron/exciton blocking layer (e)

4. light-emitting layer (c)

5. cathode (b)

Layer sequences different from the aforementioned construction are alsopossible, and are known to those skilled in the art. For example, it ispossible that the OLED does not have all of the layers mentioned; forexample, an OLED with the layers (a) (anode), (c) (light-emitting layer)and (b) (cathode) and layer (d) (hole-transport layer) or layer (e)(electron/exciton blocking layer) are likewise suitable.

The OLEDs may additionally have a blocking layer for holes/excitons (f)adjacent to the cathode side of the light-emitting layer (c) and/or anelectron transport layer (g) adjacent to the cathode side of theblocking layer for holes/excitons (f), if present, respectively adjacentto the cathode side of the light-emitting layer (c), if the blockinglayer for holes/excitons (f) is not present.

The present invention therefore more preferably relates to an inventiveOLED having the following layer sequence:

1. anode (a)

2. hole-transport layer (d)

3. electron/exciton blocking layer (e)

4. light-emitting layer (c)

5. blocking layer for holes/excitons (f)

6. electron transport layer (g)

7. cathode (b)

In a further embodiment, the inventive OLED, in addition to layers (a),(b), (c), (d), (e), (f) and (g), comprises at least one of the furtherlayers mentioned below:

-   -   A hole injection layer (h) between the anode (a) and the        hole-transport layer (d);    -   an electron injection layer (i) between the electron-transport        layer (g) and the cathode (b).

It is additionally possible that a plurality of the aforementionedfunctions (electron/exciton blocker, hole/exciton blocker, holeinjection, hole conduction, electron injection, electron conduction) arecombined in one layer and are assumed, for example, by a single materialpresent in this layer.

Furthermore, the individual layers of the OLED among those specifiedabove may in turn be formed from two or more layers. For example, thehole transport layer may be formed from a layer into which holes areinjected from the electrode, and a layer which transports the holes awayfrom the hole-injecting layer into the light-emitting layer. Theelectron transport layer may likewise consist of a plurality of layers,for example a layer in which electrons are injected by the electrode,and a layer which receives electrons from the electron injection layerand transports them into the light-emitting layer. These layersmentioned are each selected according to factors such as energy level,thermal resistance and charge carrier mobility, and also energydifference of the layers specified with the organic layers or the metalelectrodes. The person skilled in the art is capable of selecting thestructure of the OLEDs such that it is matched optimally to the organiccompounds used as emitter substances in accordance with the invention.

In order to obtain particularly efficient OLEDs, for example, the HOMO(highest occupied molecular orbital) of the hole-transport layer shouldbe matched to the work function of the anode, and the LUMO (lowestunoccupied molecular orbital) of the electron conductor layer should bematched to the work function of the cathode, provided that theaforementioned layers are present in the inventive OLEDs.

Hole-Transport Material (d) and/or the Electron/Exciton Blocker Material(e)

The hole-transport material and/or the electron/exciton blocker materialin the OLED of the present invention may be an Ir metal-carbene complexcomprising one, two or three, preferably three, bidentate ligands offormula (III) and/or (III′)

wherein

R^(1″), R^(2″) and R^(3″)

are each independently hydrogen, deuterium, a linear or branched alkylradical, optionally interrupted by at least one heteroatom, optionallybearing at least one functional group and having a total of from 1 to 20carbon atoms and/or heteroatoms, a substituted or unsubstitutedcycloalkyl radical, optionally bearing at least one functional group andhaving from 3 to 20 carbon atoms, a substituted or unsubstitutedheterocyclo alkyl radical, interrupted by at least one heteroatom,optionally bearing at least one functional group and having a total offrom 3 to 20 carbon atoms and/or heteroatoms, a substituted orunsubstituted aryl radical, optionally bearing at least one functionalgroup and having 6 to 30 carbon atoms, a substituted or unsubstitutedheteroaryl radical, interrupted by at least one heteroatom, optionallybearing at least one functional group and having a total of from 5 to 18carbon atoms and/or heteroatoms, a group with donor or acceptor action,preferably, R^(1″), R^(2″) and R^(3″) are each independently hydrogen, alinear or branched alkyl radical, having from 1 to 6 carbon atoms, asubstituted or unsubstituted aryl radical, having from 6 to 30 carbonatoms, a substituted or unsubstituted heteroaryl radical, having a totalof from 5 to 18 carbon atoms and/or heteroatoms, a group with donor oracceptor action, selected from the group consisting of halogen radicals,preferably F or Cl, more preferably F; CF₃, SiPh₃ and SiMe₃;

or

R^(1″) and R^(2″) or R^(2″) and R^(3″) form, independently of eachother, together with a carbon atom to which they are bonded anoptionally substituted saturated or unsaturated or aromatic ring,optionally interrupted by at least one heteroatom and having a total offrom 5 to 18 carbon atoms and/or heteroatoms, and may optionally befused to at least one further optionally substituted saturated orunsaturated or aromatic ring, optionally interrupted by at least oneheteroatom and having a total of from 5 to 18 carbon atoms and/orheteroatoms;

A^(1″) is CR^(4″) or N, preferably CR^(4″);

A^(2″) is CR^(5″) or N, preferably CR^(5″);

A^(3″) is CR^(6″) or N, preferably CR^(6″);

A^(4″) is CR^(7″) or N, preferably CR^(7″);

A^(1′″) is CR^(4′″) or N, preferably CR^(4′″);

A^(2′″) is CR^(5′″) or N, preferably CR^(5′″);

A^(3′″) is CR^(6′″) or N, preferably CR^(6′″);

A^(4′″) is CR^(7′″) or N, preferably CR^(7′″);

R^(4″), R^(5″), R^(6″), R^(7″), R^(4′″), R^(5′″), R^(6′″) and R^(7′″)

are each independently hydrogen, deuterium, a linear or branched alkylradical, optionally interrupted by at least one heteroatom, optionallybearing at least one functional group and having a total of from 1 to 20carbon atoms and/or heteroatoms, a substituted or unsubstitutedcycloalkyl radical, optionally bearing at least one functional group andhaving from 3 to 20 carbon atoms, a substituted or unsubstitutedheterocyclo alkyl radical, interrupted by at least one heteroatom,optionally bearing at least one functional group and having a total offrom 3 to 20 carbon atoms and/or heteroatoms, a substituted orunsubstituted aryl radical, optionally bearing at least one functionalgroup and having from 6 to 30 carbon atoms, a substituted orunsubstituted heteroaryl radical, interrupted by at least oneheteroatom, optionally bearing at least one functional group and havinga total of from 5 to 18 carbon atoms and/or heteroatoms, a group withdonor or acceptor action, preferably, R^(4″), R^(5″), R^(6″), R^(7″),R^(4′″), R^(5′″), R^(6′″) and R^(7′″) are each independently hydrogen, alinear or branched alkyl radical, optionally bearing at least onefunctional group, optionally interrupted by at least one heteroatom andhaving a total of from 1 to 20 carbon and/or heteroatoms, a substitutedor unsubstituted aryl radical, having from 6 to 30 carbon atoms, asubstituted or unsubstituted heteroaryl radical, having a total of from5 to 18 carbon atoms and/or heteroatoms, a group with donor or acceptoraction, selected from halogen radicals, preferably F or Cl, morepreferably F; CF₃, CN, SiPh₃ and SiMe₃;

or

R^(4″) and R^(5″), R^(5″) and R^(6″) or R^(6″) and R^(7″) or R^(4′″) andR^(5′″), R^(5′″) and R^(6′″) or R^(6′″) and R^(7′″) form, independentlyof each other, together with the carbon atoms to which they are bonded,a saturated or unsaturated or aromatic, optionally substituted ring,which is optionally interrupted by at least one heteroatom, has a totalof from 5 to 18 carbon atoms and/or heteroatoms, and may optionally befused to at least one further optionally substituted saturated orunsaturated or aromatic ring, optionally interrupted by at least oneheteroatom and having a total of from 5 to 18 carbon atoms and/orheteroatoms.

Preferred Ir metal-carbene complexes suitable as hole-transportmaterials and/or the electron/exciton blocker materials in the OLED ofthe present invention are described in detail in the EP application No.13162776.2.

In the case that the OLED comprises a material different from thematerials mentioned before in the hole-transport layer or in theelectron/exciton blocking layer, suitable materials are mentioned below.

Hole-Transport Layer (d)

Further suitable hole-transport materials for layer (d) of the inventiveOLED are disclosed, for example, in Kirk-Othmer Encyclopedia of ChemicalTechnology, 4th Edition, Vol. 18, pages 837 to 860, 1996. Eitherhole-transporting molecules or polymers may be used as thehole-transport material. Customarily used hole-transporting moleculesare selected from the group consisting of

(4-phenyl-N-(4-phenylphenyl)-N-[4-[4-(N-[4-(4-phenylphenyl)phenyl]anilino)phenyl]phenyl]aniline),

(4-phenyl-N-(4-phenylphenyl)-N-[4-[4-(4-phenyl-N-(4-phenylphenyl)anilino)phenyl]phenyl]aniline),

(4-phenyl-N-[4-(9-phenylcarbazol-3-yl)phenyl]-N-(4-phenylphenyl)aniline),

1,1′,3,3′-tetraphenylspiro[1,3,2-benzodiazasilole-2,2′-3a,7a-dihydro-1,3,2-benzodiazasilole],

(N2,N2,N2′,N2′,N7,N7,N7′,N7′-octakis(p-tolyl)-9,9′-spirobi[fluorene]-2,2′,7,7′-tetramine),4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (α-NPD),N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine(TPD), 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC),N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-[1,1′-(3,3′-dimethyl)biphenyl]-4,4′-diamine(ETPD), tetrakis(3-methylphenyl)-N,N,N′,N′-2,5-phenylenediamine (PDA),α-phenyl-4-N,N-diphenylaminostyrene (TPS), p-(diethylamino)benzaldehydediphenyihydrazone (DEH), triphenylamine (TPA),bis[4-(N,N-diethylamino)2-methylphenyl](4-methylphenyl)methane (MPMP),1-phenyl-3-[p-(diethylamino)styryl]5-[p-(diethylamino)phenyl]pyrazoline(PPR or DEASP), 1,2-trans-bis(9H-carbazol9-yl)-cyclobutane (DCZB),N,N,N′,N′-tetrakis(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine (TTB),fluorine compounds such as2,2′,7,7′-tetra(N,N-di-tolyl)amino9,9-spirobifluorene (spiro-TTB),N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)9,9-spirobifluorene(spiro-NPB) and9,9-bis(4-(N,N-bis-biphenyl-4-yl-amino)phenyl-9Hfluorene, benzidinecompounds such as N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)benzidineand porphyrin compounds such as copper phthalocyanines. In addition,polymeric hole-injection materials can be used such aspoly(N-vinylcarbazole) (PVK), polythiophenes, polypyrrole, polyaniline,self-doping polymers, such as, for example, sulfonatedpoly(thiophene-3-[2[(2-methoxyethoxy)ethoxy]-2,5-diyl) (Plexcore® OCConducting Inks commercially available from Plextronics), and copolymerssuch as poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) alsocalled PEDOT/PSS.

The hole-transport materials mentioned above are commercially availableand/or prepared by processes known by a person skilled in the art.

In a preferred embodiment it is possible to use specific metal carbenecomplexes as hole-transport materials. Suitable carbene complexes are,for example, carbene complexes as described in WO2005/019373A2,WO2006/056418 A2, WO2005/113704, WO2007/115970, WO2007/115981 andWO2008/000727. One example of a suitable carbene complex is Ir(DPBIC)₃with the formula:

The preparation of Ir(DPBIC)₃ is for example mentioned in WO 2005/019373A2.

Another example of a suitable carbene complex is Ir(DPABIC)₃

The preparation of Ir(DPABIC)₃ is for example mentioned in WO2012/172182(complex Em1; synthesis: example 1)).

Another example of a suitable carbene complex is

Ir(DPABIC)₂(DPBIC)

The preparation of Ir(DPABIC)₂(DPBIC) is for example mentioned inWO2012/172482 (complex Em10 in (synthesis: example 10)).

The hole-transporting layer may also be electronically doped in order toimprove the transport properties of the materials used, in order firstlyto make the layer thicknesses more generous (avoidance of pinholes/shortcircuits) and in order secondly to minimize the operating voltage of thedevice. Electronic doping is known to those skilled in the art and isdisclosed, for example, in W. Gao, A. Kahn, J. Appl. Phys., Vol. 94, No.1, 1 Jul. 2003 (p-doped organic layers); A. G. Wemer, F. Li, K. Harada,M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., Vol. 82, No. 25, 23Jun. 2003 and Pfeiffer et al., Organic Electronics 2003, 4, 89-103 andK. Walzer, B. Maennig, M. Pfeiffer, K. Leo, Chem. Soc. Rev. 2007, 107,1233. For example it is possible to use mixtures in thehole-transporting layer, in particular mixtures which lead to electricalp-doping of the hole-transporting layer. p-Doping is achieved by theaddition of oxidizing materials. These mixtures may, for example, be thefollowing mixtures: mixtures of the abovementioned hole transportmaterials with at least one metal oxide as doping material, for exampleMoO₂, MOO₃, WO_(x), ReO₃ and/or V₂O₅, preferably MoO₃ and/or ReO₃, morepreferably MoO₃ or mixtures comprising the aforementioned hole transportmaterials and one or more compounds selected from7,7,8,8-tetracyanoquinodimethane (TCNQ),2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F₄-TCNQ),2,5-bis(2-hydroxyethoxy)-7,7,8,8-tetracyanoquinodimethane,bis(tetra-n-butylammonium)tetracyanodiphenoquinodimethane,2,5-dimethyl-7,7,8,8-tetracyanoquinodimethane, tetracyanoethylene,11,11,12,12-tetracyanonaphtho-2,6-quinodimethane,2-fluoro-7,7,8,8-tetracyanoquino-dimethane,2,5-difluoro-7,7,8,8-tetracyanoquinodimethane,dicyanomethylene-1,3,4,5,7,8-hexafluoro-6H-naphthalen-2-ylidene)malononitrile(F₆-TNAP), Mo(tfd)₃ (from Kahn et al., J. Am. Chem. Soc. 2009, 131 (35),12530-12531), compounds as described in EP1988587 and in EP2180029 andquinone compounds as mentioned in EP 09153776.1.

Preferably, the hole-transport layer comprises 50 to 90% by weight, ofthe hole-transport material and 10 to 50% by weight of the dopingmaterial, wherein the sum of the amount of the hole-transport materialand the doping material is 100% by weight.

Electron/Exciton Blocking Layer (e)

Blocking layers may also be used to block excitons from diffusing out ofthe emissive layer.

Further suitable metal complexes for use as electron/exciton blockermaterial are, for example, carbene complexes as described in WO2005/019373 A2, WO 2006/056418 A2, WO 2005/113704, WO 2007/115970, WO2007/115981 and WO 2008/000727. Explicit reference is made here to thedisclosure of the WO applications cited, and these disclosures shall beconsidered to be incorporated into the content of the presentapplication. One example of a suitable carbene complex is Ir(DPBIC)₃with the formula:

Another example of a suitable carbene complex is Ir(DPABIC)₃

Another example of a suitable carbene complex is Ir(DPABIC)₂(DPBIC)

Anode (a)

The anode is an electrode which provides positive charge carriers. Itmay be composed, for example, of materials which comprise a metal, amixture of different metals, a metal alloy, a metal oxide or a mixtureof different metal oxides. Alternatively, the anode may be a conductivepolymer. Suitable metals comprise the metals of groups 11, 4, 5 and 6 ofthe Periodic Table of the Elements, and also the transition metals ofgroups 8 to 10. When the anode is to be transparent, mixed metal oxidesof groups 12, 13 and 14 of the Periodic Table of the Elements aregenerally used, for example indium tin oxide (ITO). It is likewisepossible that the anode (a) comprises an organic material, for examplepolyaniline, as described, for example, in Nature, Vol. 357, pages 477to 479 (Jun. 11, 1992). Preferred anode materials include conductivemetal oxides, such as indium tin oxide (ITO) and indium zinc oxide(IZO), aluminum zinc oxide (AlZnO), and metals. Anode (and substrate)may be sufficiently transparent to create a bottom-emitting device. Apreferred transparent substrate and anode combination is commerciallyavailable ITO (anode) deposited on glass or plastic (substrate). Areflective anode may be preferred for some top-emitting devices, toincrease the amount of light emitted from the top of the device. Atleast either the anode or the cathode should be at least partlytransparent in order to be able to emit the light formed. Other anodematerials and structures may be used.

The anode materials mentioned above are commercially available and/orprepared by processes known by a person skilled in the art.

Cathode (b)

The cathode (b) is an electrode which serves to introduce electrons ornegative charge carriers.

The cathode may be any metal or nonmetal which has a lower work functionthan the anode.

Suitable materials for the cathode are selected from the groupconsisting of alkali metals of group 1, for example Li, Cs, alkalineearth metals of group 2, metals of group 12 of the Periodic Table of theElements, comprising the rare earth metals and the lanthanides andactinides. In addition, metals such as aluminum, indium, calcium,barium, samarium and magnesium, and combinations thereof, may be used.

The cathode materials mentioned above are commercially available and/orprepared by processes known by a person skilled in the art.

Further Layers in the Inventive OLED

Blocking Layer for Holes/Excitons (f)

Among the materials mentioned below as electron transport materials,some may fulfil several functions. For example, some of the electrontransport materials are simultaneously hole-blocking materials when theyhave a low-lying HOMO or exciton-blocking materials when they have asufficiently high triplet energy. These can be used, for example, in theblocking layer for holes/excitons (f). However, it is likewise possiblethat the function as a hole/exciton blocker is also adopted by the layer(g), such that the layer (f) can be dispensed with.

Electron Transport Layer (g)

Electron transport layer may include a material capable of transportingelectrons. Electron transport layer may be intrinsic (undoped), ordoped. Doping may be used to enhance conductivity. Suitableelectron-transporting materials for layer (g) of the inventive OLEDscomprise metals chelated with oxinoid compounds, such astris(8-hydroxyquinolato)aluminum (Alq₃), compounds based onphenanthroline such as 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline(DDPA=BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen),2,4,7,9-tetraphenyl-1,10-phenanthroline,4,7-diphenyl-1,10-phenanthroline (DPA) or phenanthroline derivativesdisclosed in EP1786050, in EP1970371, or in EP1097981, and azolecompounds such as 2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole(PBD) and 3-(4-biphenylyl)-4phenyl-5-(4-t-butylphenyl)-1,2,4-triazole(TAZ).

The electron-transport materials mentioned above are commerciallyavailable and/or prepared by processes known by a person skilled in theart.

It is likewise possible to use mixtures of at least two materials in theelectron-transporting layer, in which case at least one material iselectron-conducting. Preferably, in such mixed electron-transportinglayers, at least one phenanthroline compound is used, preferably BCP, orat least one pyridine compound according to the formula (VIII) below,preferably a compound of the formula (VIIIa) below. More preferably, inmixed electron-transporting layers, in addition to at least onephenanthroline compound, alkaline earth metal or alkali metalhydroxyquinolate complexes, for example Liq (8-hydroxyquinolatolithium),are used. Suitable alkaline earth metal or alkali metal hydroxyquinolatecomplexes are specified below (formula VII). Reference is made toWO2011/157779.

The electron transport layer may also be electronically doped in orderto improve the transport properties of the materials used, in orderfirstly to make the layer thicknesses more generous (avoidance ofpinholes/short circuits) and in order secondly to minimize the operatingvoltage of the device. Electronic doping is known to those skilled inthe art and is disclosed, for example, in W. Gao, A. Kahn, J. Appl.Phys., Vol. 94, No. 1, 1 Jul. 2003 (p-doped organic layers); A. G.Wemer, F. Li, K. Harada, M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys.Lett., Vol. 82, No. 25, 23 Jun. 2003 and Pfeiffer et al., OrganicElectronics 2003, 4, 89-103 and K. Walzer, B. Maennig, M. Pfeiffer, K.Leo, Chem. Soc. Rev. 2007, 107, 1233. For example, it is possible to usemixtures which lead to electrical n-doping of the electron-transportinglayer. n-Doping is achieved by the addition of reducing materials. Thesemixtures may, for example, be mixtures of the above-mentioned electrontransport materials with alkali/alkaline earth metals or alkali/alkalineearth metal salts, for example Li, Cs, Ca, Sr, Cs₂CO₃, with alkali metalcomplexes, for example 8-hydroxyquinolatolithium (Liq), and with Y, Ce,Sm, Gd, Tb, Er, Tm, Yb, Li₃N, Rb₂CO₃, dipotassium phthalate, W(hpp)₄from EP 1786050, or with compounds as described in EP1 837 926 B1.

In a preferred embodiment, the electron transport layer comprises atleast one compound of the general formula (VII)

in which

R^(32′) and R^(33′) are each independently F, C₁-C₈-alkyl, orC₆-C₁₄-aryl, which is optionally substituted by one or more C₁-C₈-alkylgroups, or

two R^(32′) and/or R^(33′) substituents together form a fused benzenering which is optionally substituted by one or more C₁-C₈-alkyl groups;

a and b are each independently 0, 1, 2 or 3,

M¹ is an alkaline metal atom or alkaline earth metal atom,

p is 1 when M¹ is an alkali metal atom, p is 2 when M¹ is an alkalimetal atom.

A very particularly preferred compound of the formula (VII) is

which may be present as a single species, or in other forms such asLi_(g)Q_(g) in which g is an integer, for example Li₆Q₆. Q is an8-hydroxyquinolate ligand or an 8-hydroxyquinolate derivative.

In a further preferred embodiment, the electron-transporting layercomprises at least one compound of the formula (VIII),

in which

R^(34′), R^(35′), R^(36′), R^(37′), R^(34″), R^(35″), R^(36″) andR^(37″) are each independently hydrogen, C₁-C₁₈- alkyl, C₁-C₁₈-alkylwhich is substituted by E and/or interrupted by D, C₆-C₂₄-aryl,C₆-C₂₄-aryl which is substituted by G, C₂-C₂₀-heteroaryl orC₂-C₂₀-heteroaryl which is substituted by G,

Q is an arylene or heteroarylene group, each of which is optionallysubstituted by G;

D is —CO—; —COO—; —S—; —SO—; —SO₂—; —O—; —NR^(40′)—; —SiR^(45′)R^(46′)—;—POR^(47′)—; —CR^(38′)═CR^(39′)—; or —C≡C—;

E is —OR^(44′); —SR^(44′); —NR^(40′)R⁴¹; —COR^(43′); —COOR^(42′);—CONR^(40′)R^(41′); —CN; or F;

G is E, C₁-C₁₈-alkyl, C₁-C₁₈-alkyl which is interrupted by D,C₁-C₁₈-perfluoroalkyl, C₁-C₁₈-alkoxy, or C₁-C₁₈-alkoxy which issubstituted by E and/or interrupted by D,

in which

R^(38′) and R^(39′) are each independently H, C₆-C₁₈-aryl; C₆-C₁₈-arylwhich is substituted by C₁-C₁₈-alkyl or C₁-C₁₈-alkoxy; C₁-C₁₈-alkyl; orC₁-C₁₈-alkyl which is interrupted by —O—;

R^(40′) and R^(41′) are each independently C₆-C₁₈-aryl; C₆-C₁₈-arylwhich is substituted by C₁-C₁₈-alkyl or C₁-C₁₈-alkoxy; C₁-C₁₈-alkyl; orC₁-C₁₈-alkyl which is interrupted by —O—; or

R^(40′) and R^(41′) together form a 6-membered ring;

R^(42′) and R^(43′) are each independently C₆-C₁₈-aryl; C₆-C₁₈-arylwhich is substituted by C₁-C₁₈-alkyl or C₁-C₁₈-alkoxy; C₁-C₁₈-alkyl; orC₁-C₁₈-alkyl which is interrupted by —O—,

R^(44′) is C₆-C₁₈-aryl; C₆-C₁₈-aryl which is substituted by C₁-C₁₈-alkylor C₁-C₁₈-alkoxy; C₁-C₁₈-alkyl; or C₁-C₁-alkyl which is interrupted by—O—,

R^(45′) and R^(46′) are each independently C₁-C₁₈-alkyl, C₆-C₁₈-aryl orC₆-C₁₈-aryl which is substituted by C₁-C₁₈-alkyl,

R^(47′) is C₁-C₁₈-alkyl, C₆-C₁₈-aryl or C₆-C₁₈-aryl which is substitutedby C₁-C₁₈-alkyl.

Preferred compounds of the formula (VIII) are compounds of the formula(VIIIa)

in which Q is:

R^(48′) is H or C₁-C₁₈-alkyl and

R^(48″) is H, C₁-C₁₈-alkyl or

Particular preference is given to a compound of the formula

In a further, very particularly preferred embodiment, the electrontransport layer comprises a compound of the formula

and a compound ETM-1.

In a preferred embodiment, the electron transport layer comprises thecompound of the formula (VII) in an amount of 99 to 1% by weight,preferably 75 to 25% by weight, more preferably about 50% by weight,where the amount of the compounds of the formulae (VII) and the amountof the compounds of the formulae (VIII) adds up to a total of 100% byweight.

The preparation of the compounds of the formula (VIII) is described inJ. Kido et al., Chem. Commun. (2008) 5821-5823, J. Kido et al., Chem.Mater. 20 (2008) 5951-5953 and JP2008-127326, or the compounds can beprepared analogously to the processes disclosed in the aforementioneddocuments.

It is likewise possible to use mixtures of alkali metal hydroxyquinolatecomplexes, preferably Liq, and dibenzofuran compounds in the electrontransport layer. Reference is made to WO2011/157790. Dibenzofurancompounds A-1 to A-36 and B-1 to B-22 described in WO 2011/157790 arepreferred, wherein dibenzofuran compound

is most preferred.

In a preferred embodiment, the electron transport layer comprises Liq inan amount of 99 to 1% by weight, preferably 75 to 25% by weight, morepreferably about 50% by weight, where the amount of Liq and the amountof the dibenzofuran compound(s), especially ETM-2, adds up to a total of100% by weight.

In a preferred embodiment, the electron transport layer comprises atleast one phenanthroline derivative and/or pyridine derivative.

In a further preferred embodiment, the electron transport layercomprises at least one phenanthroline derivative and/or pyridinederivative and at least one alkali metal hydroxyquinolate complex.

In a further preferred embodiment, the electron transport layercomprises at least one of the dibenzofuran compounds A-1 to A-36 and B-1to B-22 described in WO2011/157790, especially ETM-2.

In a further preferred embodiment, the electron transport layercomprises a compound described in WO 2012/111462, WO 2012/147397 and US2012/0261654, such as, for example, a compound of formula

WO 2012/115034, such as for example, such as, for example, a compound offormula

Hole Injection Layer (h)

Generally, injection layers are comprised of a material that may improvethe injection of charge carriers from one layer, such as an electrode ora charge generating layer, into an adjacent organic layer. Injectionlayers may also perform a charge transport function. The hole injectionlayer may be any layer that improves the injection of holes from anodeinto an adjacent organic layer. A hole injection layer may comprise asolution deposited material, such as a spin-coated polymer, or it may bea vapor deposited small molecule material, such as, for example, CuPc orMTDATA. Polymeric hole-injection materials can be used such aspoly(N-vinylcarbazole) (PVK), polythiophenes, polypyrrole, polyaniline,self-doping polymers, such as, for example, sulfonatedpoly(thiophene-3-[2[(2-methoxyethoxy)ethoxy]-2,5-diyl) (Plexcore® OCConducting Inks commercially available from Plextronics, e.g. PlexcoreAJ20-1000), and copolymers such aspoly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) also calledPEDOT/PSS.

The hole injection materials mentioned above are commercially availableand/or prepared by processes known by a person skilled in the art.

Electron Injection Layer (i)

The electron injection layer may be any layer that improves theinjection of electrons into an adjacent organic layer.Lithium-comprising organometallic compounds such as8-hydroxyquinolatolithium (Liq), CsF, NaF, KF, Cs₂CO₃ or LiF may beapplied between the electron transport layer (g) and the cathode (b) asan electron injection layer (i) in order to reduce the operatingvoltage.

The electron injection materials mentioned above are commerciallyavailable and/or prepared by processes known by a person skilled in theart.

In general, the different layers in the inventive OLED, if present, havethe following thicknesses:

anode (a): 50 to 500 nm, preferably 100 to 200 nm;

a hole injection layer (h): 5 to 100 nm, preferably 20 to 80 nm,

hole-transport layer (d): 5 to 100 nm, preferably 10 to 80 nm,

electron/exciton blocking layer (e): 1 to 50 nm, preferably 5 to 10 nm,

light-emitting layer (c): 1 to 100 nm, preferably 5 to 60 nm,

a hole/exciton blocking layer (f): 1 to 50 nm, preferably 5 to 10 nm,

electron-transport layer (g): 5 to 100 nm, preferably 20 to 80 nm,

electron injection layer (i): 1 to 50 nm, preferably 2 to 10 nm,

cathode (b): 20 to 1000 nm, preferably 30 to 500 nm.

The person skilled in the art is aware (for example on the basis ofelectrochemical studies) of how suitable materials have to be selected.Suitable materials for the individual layers are known to those skilledin the art and are disclosed, for example, in WO 00/70655.

In addition, it is possible that some of the layers used in theinventive OLED have been surface-treated in order to increase theefficiency of charge carrier transport. The selection of the materialsfor each of the layers mentioned is preferably determined by obtainingan OLED with a high efficiency and lifetime.

The inventive organic electronic device, preferably OLED, can beproduced by methods known to those skilled in the art. In general, theinventive OLED is produced by successive vapor deposition of theindividual layers onto a suitable substrate. Suitable substrates are,for example, glass, inorganic semiconductors or polymer films. For vapordeposition, it is possible to use customary techniques, such as thermalevaporation, chemical vapor deposition (CVD), physical vapor deposition(PVD) and others. In an alternative process, the organic layers of theorganic electronic device, preferably OLED, can be applied fromsolutions or dispersions in suitable solvents, employing coatingtechniques known to those skilled in the art.

The relative position of the recombination zone of holes and electronsin the inventive OLED in relation to the cathode and hence the emissionspectrum of the OLED can be influenced, among other factors, by therelative thickness of each layer. This means that the thickness of theelectron transport layer should preferably be selected such that theposition of the recombination zone is matched to the optical resonatorproperty of the diode and hence to the emission wavelength of theemitter. The ratio of the layer thicknesses of the individual layers inthe OLED depends on the materials used. The layer thicknesses of anyadditional layers used are known to those skilled in the art. It ispossible that the electron-conducting layer and/or the hole-conductinglayer has/have greater thicknesses than the layer thicknesses specifiedwhen they are electrically doped.

In a further embodiment the present invention relates to the use of acyclometallated Ir complex of formula (I) according to the presentinvention in an OLED, preferably as emitter material. Suitable andpreferred cyclometallated Ir complexes of formula (I) and suitable andpreferred OLEDs are mentioned above. The emitter material is present inthe light-emitting layer of the OLED.

Use of at least one cyclometallated Ir complex of formula (I) accordingto the present invention in an OLED, preferably as emitter materialmakes it possible to obtain OLEDs with high efficiency and/or highluminous efficacy and/or with high stability and especially longlifetimes.

The organic electronic devices, preferably OLEDs, can be used in allapparatus in which electroluminescence is useful. Suitable devices arepreferably selected from the group consisting of stationary visualdisplay units, such as visual display units of computers, televisions,visual display units in printers, kitchen appliances, advertisingpanels, information panels and illuminations; mobile visual displayunits such as visual display units in smartphones, cellphones, tabletcomputers, laptops, digital cameras, MP3-players, vehicles, keyboardsand destination displays on buses and trains; illumination units; unitsin items of clothing; units in handbags, units in accessories, units infurniture and units in wallpaper.

The present invention therefore further relates to apparatus selectedfrom the group consisting of stationary visual display units, such asvisual display units of computers, televisions, visual display units inprinters, kitchen appliances, advertising panels, information panels andilluminations; mobile visual display units such as visual display unitsin smartphones, cellphones, tablet computers, laptops, digital cameras,MP3-players, vehicles, keyboards and destination displays on buses andtrains; illumination units; units in items of clothing; units inhandbags, units in accessories, units in furniture and units inwallpaper, comprising at least one organic electronic device, preferablyat least one OLED, according to the present invention or comprising atleast one hole transport layer or at least one electron/exciton blockinglayer according to the present invention or comprising at least onecyclometallated Ir complex of formula (I) according to the presentinvention.

In a further embodiment, the cyclometallated Ir complex of formula (I)can be used in white OLEDs.

The OLEDs may further comprise at least one second light-emitting layer.The overall emission of the OLEDs may be composed of the emission of theat least two light-emitting layers and may also comprise white light, asdescribed for example in EP13160198.1.

In addition, the cyclometallated Ir complex of formula (I) can be usedin OLEDs with inverse structure. The structure of inverse OLEDs and thematerials typically used therein are known to those skilled in the art.

It is also possible to stack two OLEDs or to stack three or more OLEDs(“stacked device concept”). These devices usually use a transparentcharge generating interlayer such as indium tin oxide (ITO), V₂O₅, or anorganic p-n junction.

The stacked OLED (SOLED) usually includes at least two individualsub-elements.

Each sub-element comprises at least three layers: an electron transportlayer, an emitter layer and a hole-transport layer. Additional layersmay be added to a sub-element. Each SOLED sub-element may include forexample a hole injection layer, a hole transport layer, anelectron/exciton blocking layer, an emitter layer, a hole/excitonblocking layer, an electron transport layer, an electron injectionlayer. Each SOLED sub-element may have the same layer structure ordifferent layer structure from the other sub-elements.

Suitable SOLED structures are known by a person skilled in the art.

Not only the organic electronic devices as mentioned above are a subjectof the present invention but also all cyclometallated Ir complexes offormula (I) as described in the present application.

In a further embodiment, the present invention relates to acyclometallated Ir of formula (I) as described in the presentapplication, and to a process for preparing the inventive metal-carbenecomplex, by contacting suitable compounds comprising Ir with appropriateligands or ligand precursors. A suitable process is described above.

The present invention further relates to the use of the inventivecyclometallated Ir complex of formula (I) as described in the presentapplication in organic electronic devices, preferably in OLEDs, morepreferably as emitter materials in OLEDs. Suitable organic electronicdevices and suitable OLEDs are described above.

The following examples are included for illustrative purposes only anddo not limit the scope of the claims.

EXAMPLES

The examples which follow, more particularly the methods, materials,conditions, process parameters, apparatus and the like detailed in theexamples, are intended to support the present invention, but not torestrict the scope of the present invention.

All experiments are carried out in protective gas atmosphere.

The percentages and ratios mentioned in the examples below—unless statedotherwise—are % by weight and weight ratios.

A Synthesis of the Inventive Ir Complexes 1 Synthesis of

Complex 1 1.1 Intermediate 1

1-Phenylamino-2-chloropyrazine (the synthesis is described in the notyet published European patent application EP13178675.8) (11.8 g, 57.4mmol) is dissolved in anhydrous THF (300 mL). o-Toluidine (7.39 g, 68.9mmol),2-(dicyclohexylphosphino)-3,6-dimethoxy-2,4,6-tri-Isopropyl-1,1-biphenyl(BrettPhos) (0.31 g, 0.57 mmol) andchloro[2-(dicyclohexylphosphino)-3,6-dimethoxy-2′,4′,6′-tri-i-propyl-1,1′-biphenyl][2-(2-aminoethyl)phenyl]palladium(II)(0.47 g, 0.57 mmol) are added. To the solution cesium carbonate (22.7 g,68.9 mmol) is added. The suspension is stirred at 80° C. for 24h. Aftercooling to room temperature, the suspension is filtered. The filtrate isreduced under vacuum and the residue is dissolved in 200 mL of hotacetonitrile. The hot solution is cooled to 20° C. and 200 mL ofn-pentane is added. Then the mixture is cooled to −15° C. After 5minutes stirring at this temperature the precipitate is filtered off andwashed with cold n-pentane. The solid is dried at 30° C. under vacuum togive 11.0 g of the desired product. The acetonitrile/n-pentane filtrateis evaporated and the residue is dissolved in 100 mL of hotacetonitrile. The hot solution is cooled to 20° C. and 100 mL ofn-pentane are added. Then the mixture is cooled to −15° C. After 5minutes stirring at this temperature the precipitate is filtered off andwashed with cold n-pentane to give 2.80 g of the desired product. Thecollected solids give 13.8 g of the desired product in 87% yield. ¹H-NMR(CD₂Cl₂): δ=2.17 (s, 3H), 6.03 (s, 1H), 6.32 (s, 1H), 6.99-7.07 (m, 2H),7.17 (t, 1H), 7.22 (d, 1H), 7.31 (d, 4H), 7.35 (d, 1H), 7.74 (d, 2H).

1.2 Intermediate 2

Intermediate 1 (1.52 g, 5.50 mmol) is dissolved in 27.5 mL ofhydrochloric acid in methanol (c=1 mol/L). The reaction is stirred atroom temperature overnight. The resulting suspension is cooled to 0-5°C. and then it is filtered and washed first with the filtrate, then withpetrol ether. The solid is dried at 60° C. under vacuum to give 1.49 gof the desired product (87% yield). ¹H-NMR (CD₂Cl₂): δ=2.25 (s, 3H),7.08 (t, 1H), 7.25-7.32 (m, 3H), 7.35-7.39 (m, 4H), 7.52 (s, 1H), 7.87(d, 2H), 9.9 (br. s, 1H), 10.3 (br. s, 1H).

1.3 Intermediate 3

Intermediate 2 (1.33 g, 4.26 mol) and molecular sieves (5 Å and 3 Å, 3 geach) are added in a flask. Then 28 mL of trimethylorthoformate areadded. The mixture is purged with argon and then heated to reflux for1.5h. After cooling to room temperature, the mixture is evaporated undervacuum. Then the residue is dissolved in dichloromethane and evaporatedagain (3×). The residue is directly used in the next step. ¹H-NMR(CD₂Cl₂): δ=2.27 (s, 3H), 3.20 (s, 3H), 7.13 (s, 1H), 7.18 (t, 1H),7.30-7.40 (m, 5H), 7.41-7.47 (m, 3H), 8.03 (d, 2H).

1.4 Complex 1 (Fac und Mer)

Intermediate 3 (1.36 g, 4.26 mmol) is dissolved in 40 mL of anhydrouso-xylene under argon. Thendi-μ-chloro-bis[(cycloocta-1,5-dien)iridium(I)] (0.29 g, 0.43 mmol) isadded to the solution. After degassing the solution with argon flux, thereaction is heated up to 140° C. overnight. The solvent of the reactionmixture is removed and the residue is purified by column chromatography(silica). One fraction yields 140 mg of the fac isomer (15%). The solidobtained from another fraction is stirred in a solution ofacetone/acetonitrile and precipitated by addition of acetone to yield295 mg of the mer isomer (33%).

fac isomer: ¹H-NMR (CD₂Cl₂): δ=0.68 (s, 9H), 6.49-6.55 (m, 6H), 6.66 (t,3H), 6.77 (t, 3H), 6.87 (d, 3H), 7.05 (t, 3H), 7.84 (d, 3H), 8.07 (d,3H), 8.24 (d, 3H), 8.44 (d, 3H).

Photoluminescence (2% film in PMMA): λ_(max)=475 nm; τ₀=3.0 μs;PLQY=93%.

mer isomer MALDI-MS: m/z=1047.228.

Photoluminescence (2% film in PMMA): λ_(max)=521 nm; τ₀=1.2 μs;PLQY=75%.

2 Synthesis of

Complex 2; Mer Complex 2.1 Intermediate 1

5,6-dichloropyridine-3-carboxylic acid (33 g, 0.17 mol) is dissolved in310 mL of THF. To this solution thionyl chloride (26.2 mL, 0.22 mol) isadded. Then 0.17 mL of DMF is added. The reaction mixture is stirred for2.5h at 50° C. After cooling to room temperature, the reaction mixtureis poured into 390 mL of a concentrated ammonia solution (25%) and 500mL of water. The mixture is cooled to 0° C. and stirred overnight toroom temperature. The THF is reduced under vacuum, the aqueous solutionis extracted with ethyl acetate. The organic layer is washed with water,followed by a sodium hydroxide solution (10%). After drying overanhydrous sodium sulfate the solvent is reduced. The residue is driedunder vacuum to give 30.9 g of the desired product in 95% yield. ¹H-NMR(DMSO): δ=7.83 (s, 1H), 8.28 (s, 1H), 8.49 (s, 1H), 8.81 (s, 1H).

2.2 Intermediate 2

Intermediate 1 (8.4 g, 44 mmol) is suspended in 76 mL of thionylchloride. The reaction mixture is stirred under reflux for 72h. Thesolvent is reduced under vacuum and the residue is dissolved inchloroform. The organic layer is washed with water and dried overanhydrous sodium sulfate. After reducing the solvent under vacuum, thesolid is first purified via column chromatography (reversed phase,eluent: acetonitrile/dichloromethane) and then crystallized in ethylacetate to give the title product in 78% yield (5.95 g). ¹H-NMR (CDCl₃):δ=8.05 (s, 1H), 8.60 (s, 1H).

2.3 Intermediate 3

Intermediate 2 (10.0 g, 58 mmol), 4-tert-butylphenylamine (9.5 g, 64mmol) and 30 mL of diisopropylethylamine are suspended in 200 mL ofdimethylacetamide under argon atmosphere. The suspension is heated to120° C. and stirred overnight. After cooling to room temperature, theremaining liquid is removed and the residue is taken up in methylenechloride. The organic phase is sequentially washed with hydrochloricacid (5%), a saturated sodium hydrogen carbonate solution and finallywith water. The organic layer is dried over anhydrous sodium sulfate.The remaining solution is filtered over silica, then the solvent isremoved and the solid dried at 40° C. under vacuum. The yellow productis crystallized in ethyl acetate to give the title product as a whitepowder (15.5 g) in 93% yield. ¹H-NMR (400 MHz, CDCl₃): δ=1.33 (s, 9H),7.28 (br. s, 1H), 7.41 (d, 2H), 7.50 (d, 2H), 7.75 (d, 1H), 8.38 (d,1H).

2.4 Intermediate 4

Intermediate 3 (13.2 g, 46.2 mmol) is suspended in 150 mL of THF. Then8.94 g (64.7 mmol) potassium carbonate, 248 mg (1.16 mmol)2-(dicyclohexylphosphino)-3,6-dimethoxy-2,4,6-tri-Isopropyl-1,1-biphenyl,369 mg (1.16 mmol)chloro-[2-(dicyclohexylphosphino)-3,6-dimethoxy-2,4,6-tri-Isopropyl-1,1-biphenyl]-[2-(2-aminoethyl)phenyl]palladium(II)and 4.95 g (46.2 mmol) o-toluidine are added under argon atmosphere. Themixture is stirred for 48h at 66° C. After cooling to room temperature,the reaction is diluted with 500 mL of methylene chloride. The organicphase is washed with water, then dried over anhydrous sodium sulfate andthe solvents are removed. The residue is dissolved in methylene chlorideand filtered over silica. After removing the solvent the brown oil ispurified via column chromatography (silica, cyclohexane/ethyl acetate)and the desired product is obtained in 46% yield (7.52 g).

¹H-NMR (400 MHz, CDCl₃): δ=1.31 (s, 9H), 2.27 (s, 3H), 5.00 (s, 1H),6.67 (d, 1H), 6.98 (t, 1H), 7.14 (t, 1H), 7.23 (d, 2H), 7.31 (s, 1H),7.36 (d, 2H), 7.43 (d, 2H), 8.29 (d, 1H).

2.5 Intermediate 5

Intermediate 4 (3.15 g, 8.84 mmol) is dissolved in 107 mL ofacetonitrile under argon atmosphere. The mixture is degassed with argonfor 5 minutes and then cooled to 0° C. (Chloromethylene)dimethylammoniumchloride (3.4 g, 26.5 mmol) is added. The mixture is stirred at 0-15° C.for 24h. Then 3.98 g (26.5 mmol) sodium iodide is added at 0° C. to thereaction. The mixture is stirred at 0-12° C. overnight. The suspensionis filtered and the residue is washed with cold acetonitrile. Thefiltrate is evaporated and dissolved in acetonitrile. This solution iswashed with petrol ether. The acetonitrile phase is evaporated again togive an oily residue. The oil is mixed with a mixture of methyltert-butyl ether and methylene chloride (3:1). A yellow precipitate isfalling out. The suspension is stirred overnight, then filtered andwashed with a mixture of methyl tert-butyl ether and methylene chloride(3:2). The residue is dried at 40° C. under vacuum to give 5.69 g of thedesired product. ¹H-NMR (400 MHz, CD₂Cl₂): δ=1.42 (s, 9H), 2.33 (s, 3H),7.54-7.59 (m, 2H), 7.68 (t, 1H), 7.75 (d, 2H), 8.13 (d, 1H), 8.20 (t,3H), 8.40 (s, 1H), 9.09 (s, 1H), 10.91 (s, 1H).

2.6 Intermediate 6

Intermediate 5 (2.8 g, 6.0 mmol) is dissolved in 60 mL of methanol underargon atmosphere. The mixture is cooled to 0° C. Sodium methanolate (325mg, 6.0 mmol) is added to the solution. The mixture is stirred at 0° C.up to room temperature overnight. The resulting suspension is filteredand washed with cold methanol. The residue is dried at 40° C. undervacuum. The desired product is obtained as a solid in 55% yield (1.04g). ¹H-NMR (400 MHz, CD₂Cl₂): δ=1.35 (s, 9H), 2.25 (s, 3H), 3.19 (s,3H), 6.42 (s, 1H), 7.08 (s, 1H), 7.33-7.41 (m, 4H), 7.48 (d, 2H), 7.84(d, 2H), 7.93 (d, 1H).

2.7 Complex 2 (Mer Complex)

Intermediate 6 (0.97 g, 2.43 mmol) is added to a mixture of 58 mL ofo-xylene and 163 mg (0.243 mmol)di-μ-chloro-bis[(cycloocta-1,5-dien)iridium(I)]. After degassing themixture with argon for 5 minutes, the reaction is heated up to 140° C.overnight. After cooling to room temperature, the reaction mixture isfiltered and the residue is washed with o-xylene. The filtrate isevaporated under vacuum and the obtained residue is purified via columnchromatography (silica, cyclohexane/ethyl acetate) to give 863 mg of thedesired product. The solid is stirred in a solution ofacetone/acetonitrile (1:1; 8 mL) overnight, filtered and washed withclean acetone/acetonitrile mixture (1:1) to give 495 mg of the desiredproduct (79%). MALDI-MS: m/z=1289.501.

Photoluminescence (2% film in PMMA): λ_(max)=512 nm; τ₀=0.9 μs;PLQY=80%.

3 Synthesis of

Complex 3; Mer Complex 3.1 Intermediate 1

40.0 g (0.19 mol) 5-(trifluoromethyl)-2,3-dichloropyridine, 19.0 g (0.20mol) aniline and 91.8 g (0.71 mol) diisopropylethylamine are dissolvedin 200 mL of DMA. The mixture is purged with argon for 10 minutes andthen heated to 110° C. overnight. The orange solution is evaporatedunder vacuum and the residue is dried in vacuum at 80° C. for 1.5h. Theresidue is heated in 250 mL of toluene and activated char coal. Afterfiltration and evaporating the solvent, the residue is dissolved againin toluene and filtered over silica. The filtrate is again evaporatedunder vacuum, then dissolved in dichloromethane and filtered. The yellowsolution is concentrated and dried to give 13.1 g of the desired productin 26% yield. ¹H-NMR (400 MHz, CD₂Cl₂): δ=7.13 (t, 1H), 7.29 (br. s,1H), 7.36 (t, 2H), 7.64 (d, 2H), 7.80 (d, 1H), 8.36 (d, 1H).

3.2 Intermediate 2

8.80 g (63.7 mmol) potassium carbonate, 5.45 g (50.9 mmol) o-toluidine,0.61 g (1.14 mmol)2-(dicyclohexylphosphino)-3,6-dimethoxy-2,4,6-triisopropyl-1,1-biphenyland 0.91 g (1.14 mmol)chloro[2-(dicyclohexylphosphino)-3,6-dimethoxy-2′,4′,6′-tri-i-propyl-1,1′-biphenyl][2-(2-aminoethyl)phenyl]palladium(II)are added to a solution of intermediate 1 (13.0 g, 47.7 mmol) in 500 mLof THF. The reaction mixture is degassed with argon and then heated toreflux overnight. After cooling to room temperature, the suspension isfiltered and washed with dichloromethane. The filtrate is concentrated.The residue is dissolved in toluene and filtered over 7 cm silica columnto give 13.7 g of the product in 83% yield. ¹H-NMR (400 MHz, CD₂Cl₂):δ=2.29 (s, 3H), 5.10 (s, 1H), 6.64-6.69 (m, 1H), 6.91-7.42 (m, 8H),7.54-7.59 (m, 2H), 8.29 (s, 1H).

3.3 Intermediate 3

Intermediate 2 (13.7 g, 39.8 mmol) is suspended in 50 mL of toluene. Tothis mixture 20 mL of hydrochloric acid (32%) are added. After 10minutes the suspension is diluted with 50 mL of toluene and the reactionis stirred overnight at room temperature. The suspension is filtered andwashed with toluene. The residue is dried at 50° C. under vacuum to give12.4 g of the desired product in 82% yield. ¹H-NMR (400 MHz, DMSO):δ=2.19 (s, 3H), 6.81 (s, 1H), 6.99-7.09 (m, 3H), 7.21 (t, 1H), 7.29 (d,1H), 7.35 (t, 2H), 7.75 (d, 2H), 8.00 (s, 1H), 9.02 (br. s, 1H).

3.4 Intermediate 4

Intermediate 3 (12.0 g, 31.6 mmol) is suspended in 120 mL oftrimethylorthoformate. The suspension is degassed with argon and thenheated to 120° C. overnight. The orange solution is concentrated undervacuum to give 12.2 g of a brown oil which is used without furtherpurification. ¹H-NMR (400 MHz, DMSO): δ=2.26 (s, 3H), 3.10 (s, 3H), 6.40(s, 1H), 7.22 (t, 1H), 7.35-7.61 (m, 7H), 7.93 (s, 1H), 8.04 (d, 2H).

3.5 Complex 3 (Mer Complex)

Intermediate 4 (2.48 g, 6.44 mmol) is dissolved in 60 ml xylene.Molecular sieve (3 Å, 2.5 g) and thendi-μ-chloro-bis[(cycloocta-1,5-dien)iridium(I)] (432 mg, 0.643 mmol) areadded to the solution. After degassing the solution with argon for 30minutes, the reaction is stirred overnight at 120° C. After cooling toroom temperature, the solid residues are removed by filtration andwashed with dichloromethane. The solvent is removed and the residue isdissolved in toluene. The solution is stirred overnight. The precipitateis filtered off and the filtrate is concentrated under vacuum. Theresidue is purified via column chromatography (silica, cyclohexane/ethylacetate). The resulting product is stirred in MTBE overnight, thenfiltered and dried. The product is obtained as a yellow solid in 49%yield (780 mg).

Photoluminescence (2% film in PMMA): λ_(max)=488 nm; τ₀=0.9 μs;PLQY=91%.

4 Synthesis of

Complex 4, Mer Complex 4.1 Intermediate 1

2-Chloro-3-iodopyridine (4.22 g, 17.6 mmol) is dissolved in toluene (50mL) and degassed under argon flux. Then palladium(II)acetate (117 mg,0.52 mmol), (R)-BINAP (333 mg, 0.53 mmol), cesium carbonate (5.38 g,16.5 mmol) and o-toluidine (1.90 g, 17.7 mmol) are added.

The mixture is heated to reflux and stirred for 72 h. After cooling toroom temperature, the reaction mixture is filtered and the filtrate isconcentrated under vacuum. The residue is purified by columnchromatography (silica, eluent: toluene). The product is obtained in 73%yield (2.81 g). ¹H-NMR (400 MHz, CD₂Cl₂): δ=2.24 (s, 3H), 5.94 (s, 1H),7.05 (d, 2H), 7.12 (m, 1H), 7.22 (d, 2H), 7.29 (d, 1H), 7.78 (t, 1H).

4.2 Intermediate 2

Intermediate 1 (1.80 g, 8.23 mmol) is dissolved in toluene (42 mL) anddegassed with an argon flux. Thentris(dibenzylidenacetone)dipalladium(0) (113 mg, 0.12 mmol), (R)-BINAP(234 mg, 0.38 mmol), sodium tert-butoxide (1.15 g, 12.0 mmol) andaniline (0.92 g, 9.88 mmol) are added. The suspension is heated toreflux and stirred for 3 d. After cooling to room temperature, thereaction mixture is filtered and the residue is washed withdichloromethane. The filtrate is concentrated under vacuum. Then theresidue is dissolved in dichloromethane and silica is added to thesolution, till the color of the overlaying solvent is orange. Themixture is filtered with dichloromethane over a layer of silica and theproduct is obtained in 92% yield (2.08 g). ¹H-NMR (400 MHz, CD₂Cl₂):δ=2.29 (s, 3H), 5.07 (s, 1H), 6.61 (d, 1H), 6.78 (q, 1H), 6.85 (t, 1H),6.91 (s, 1H), 6.96 (t, 1H), 7.05 (t, 1H), 7.19 (d, 1H), 7.27 (t, 3H),7.53 (d, 2H), 8.05 (d, 1H).

4.3 Intermediate 3

Intermediate 2 (1.41 g, 5.12 mmol) and ammonium iodide (0.78 g, 5.38mmol) are suspended in triethylorthoformate (8.5 mL) under argon. Themixture is heated to 80° C. and stirred for 3 d. The formed suspensionis filtered and the product is obtained in 52% yield (1.11 g). ¹H-NMR(400 MHz, CD₂Cl₂): δ=2.31 (s, 3H), 7.58 (m, 2H), 7.71 (m, 5H), 7.89 (d,1H), 7.96 (d, 1H), 8.32 (d, 2H), 8.89 (d, 1H), 11.15 (s, 1H).

4.4 Complex 4 (Mer Complex)

Intermediate 3 (300 mg, 0.93 mmol) and molecular sieve 3 Å (4 g) aresuspended in anhydrous 1,4-dioxane (20 mL). The suspension is degassedwith argon flux and then silver oxide (163 mg, 0.70 mmol) is added. Thereaction is stirred in the dark at room temperature for 20 h. Then adegassed solution of di-μ-chloro-bis[(cycloocta-1,5-dien)iridium(I)] (63mg, 0.09 mmol) in anhydrous o-xylene (20 mL) is added to the suspension.The mixture is heated to 150° C. and the 1,4-dioxane is distilled off.The resulting suspension is stirred at reflux over the weekend. Thereaction mixture is filtered over a thin layer of silica and the residueis washed with o-xylene. The received filtrate is concentrated undervacuum and purified by column chromatography (silica, eluent:cyclohexane/ethyl acetate). The product is obtained in 26% yield (52mg). MALDI-MS: m/z=1043.588.

Photoluminescence (2% film in PMMA): λ_(max)=453 nm; τ₀=0.9 μs;PLQY=72%.

Synthesis of

Complex 5 5.1 Intermediate 1

4-Bromo-2-methylaniline (20.0 g, 0.11 mol), phenylboronic acid (19.8 g,0.16 mol) and Pd(dppf)Cl₂*CH₂Cl₂ (4.4 g, 5.4 mmol) are suspended intoluene (1000 mL) under argon atmosphere. Then a 3 M sodium hydroxidesolution (108 mL) is added dropwise to the suspension. The mixture isheated to 90° C. and stirred overnight. After cooling to roomtemperature the reaction mixture is filtered over a layer of celite andthe filtrate is concentrated under vacuum. The residue is dissolved indichloromethane and extracted with water and a saturated sodium hydrogencarbonate solution. The organic layer is dried over sodium sulfate andthe solvent is removed. The remaining brown oil is purified by columnchromatography (silica, eluent: cyclo-hexane/ethyl acetate) to obtainthe product in 66% yield (13.1 g). ¹H-NMR (400 MHz, CD₂Cl₂): δ=2.21 (s,3H), 3.70 (s, 2H), 6.72 (d, 1H), 7.25 (m, 2H), 7.31 (s, 1H), 7.37 (t,2H), 7.53 (q, 2H).

5.2 Intermediate 2

1-Phenylamino-2-chloropyrazine (14.6 g, 0.071 mol) is suspended intetrahydrofuran (300 mL) under argon atmosphere. Then2-(dicyclohexylphosphino)-3,6-dimethoxy-2,4,6-tri-Isopropyl-1,1-biphenyl(BrettPhos) (389 mg, 0.71 mmol) is added and stirred until it is solved.The same procedure is done withchloro[2-(dicyclohexylphosphino)-3,6-dimethoxy-2′,4′,6′-tri-i-propyl-1,1′-biphenyl][2-(2-aminoethyl)phenyl]palladium(II)(579 mg, 0.71 mmol). Then cesium carbonate (27.8 g, 0.085 mol) andintermediate 1 (13.0 g, 0.071 mol) are added to the solution. Thesuspension is heated to 78° C. and stirred for 22h. After cooling toroom temperature the mixture is filtered under vacuum and the residuewashed with tetrahydrofuran. The concentrated filtrate yields 26.1 gproduct which is used for the next step without further purification.¹H-NMR (400 MHz, DMSO): δ=2.24 (s, 3H), 6.99 (t, 1H), 7.33 (q, 3H), 7.47(m, 5H), 7.54 (d, 1H), 7.56 (s, 1H), 7.68 (d, 2H), 7.72 (d, 2H), 8.074(s, 1H), 8.513 (s, 1H).

5.3 Intermediate 3

Intermediate 2 (1.5 g, 4.25 mmol) is suspended in 32% hydrochloric acid(40 mL) and stirred at room temperature overnight. Then water (40 mL) isadded and the mixture is stirred at room temperature for 2 d. Thesuspension is filtered and the solid is washed with diethyl ether anddried in vacuum. The filtrate is concentrated under vacuum, dissolved inmethanol and precipitated with water. The precipitate is filtered,washed with diethyl ether and also dried in a vacuum oven. The combinedresidues give 1.63 g product in 98% yield. ¹H-NMR (400 MHz, DMSO):δ=2.26 (s, 3H), 7.02 (t, 1H), 7.35 (q, 3H), 7.45 (m, 4H), 7.53 (q, 2H),7.59 (d, 1H), 7.69 (d, 2H), 7.76 (d, 2H), 8.63 (s, 1H), 8.87 (d, 2H).

5.4 Intermediate 4

Intermediate 3 (1.97 g, 5.1 mmol) is dissolved in triethyl orthoformate(50 mL) under argon atmosphere. The mixture is heated to 100° C. andstirred for 1h. The solution is diluted with dichloromethane and thesolvent is evaporated under vacuum. The resulting solid (1.97 g) is usedfor the next step without further purification. ¹H-NMR (400 MHz,CD₂Cl₂): δ=1.09 (t, 3H), 2.34 (s, 3H), 3.37-3.44 (m, 1H), 3.53-3.62 (m,1H), 7.15 (s, 1H), 7.18 (t, 1H), 7.35-7.40 (m, 2H), 7.41-7.49 (m, 6H),7.56 (dd, 1H), 7.61 (s, 1H), 7.64 (d, 2H), 8.05 (d, 2H).

5.5 Complex 5 (Fac und Mer)

Intermediate 4 (1.97 g, 4.8 mmol) anddi-μ-chloro-bis[(cycloocta-1,5-dien)iridium(I)] (324 mg, 0.48 mmol) aresuspended in anhydrous o-xylene (138 mL) and the suspension is degassedunder argon flux. The mixture is heated to 140° C. and stirredovernight. The suspension is cooled to room temperature and the solid isfiltered off. The filtrate is concentrated and the residue is purifiedby column chromatography (eluent: cyclohexane/dichloromethane). Thesolid of one fraction is stirred in a mixture of acetone/acetonitrile1:1 to yield 99 mg of the fac isomer (8%). Another fraction is purifiedfurther by stirring in a mixture of acetone/acetonitrile 1:1 to yield410 mg of the mer isomer (33%).

fac isomer: ¹H-NMR (CD₂Cl₂): δ=0.77 (s, 9H), 6.48 (dd, 3H), 6.65 (dt,3H), 7.06 (dt, 3H), 7.22-7.38 (m, 21H), 7.70 (d, 3H), 7.80 (d, 3H), 8.10(d, 3H), 8.50 (d, 3H).

Photoluminescence (2% film in PMMA): λ_(max)=471 nm; τ₀=3.7 μs;PLQY=90%.

mer isomer Photoluminescence (2% film in PMMA): λ_(max)=521 nm; τ₀=1.1μs; PLQY=70%.

6 Synthesis of

Complex 6; Mer Complex 6.1 Intermediate 1

4-bromo-2-fluoronitrobenzene (1.0 g, 4.3 mmol) and aniline (490 mg, 5.2mmol) are suspended in 1-methyl-2-pyrrolidon (2 mL). The mixture ispurged with argon, then heated to 50° C. for 15 h. Additional aniline(350 mg, 3.7 mmol) is added to the reaction. The mixture is stirred at50° C. for 15 h. After cooling to room temperature the mixture isdiluted with 2 mL of methanol and 15 mL of water. The obtainedprecipitate is filtered and washed twice with methanol/water-solution(2:1). The solid is dried at 60° C. under vacuum. The desired product isobtained in 88% yield (1.1 g). ¹H-NMR (400 MHz, CD₂Cl₂): δ=6.89 (d, 1H),7.32-7.26 (m, 3H), 7.33 (s, 1H), 7.46 (t, 2H), 8.05 (d, 1H), 9.47 (s,1H).

6.2 Intermediate 2

Intermediate 1 (1.0 g, 4.3 mmol) is suspended in 10 mL of dioxane and2.5 mL of 5N NaOH solution. The mixture is purged with argon. Then2-methylphenylboronic acid (1.09 g, 7.86 mmol) and Pd[P(tBu)₃]₂ (75 mg,0.14 mmol) are added under argon atmosphere. The reaction mixture isheated to 85° C. and stirred for 15 h. After cooling to room temperaturethe reaction mixture is filtered over celite and washed withdichloromethane. The combined organic layers are washed with water,dried over anhydrous sodium sulphate and concentrated under vacuum. Theresidue is purified via column chromatography (silica, eluent:n-hexane/THF) and the desired product is obtained in 93% yield (1.2 g).¹H-NMR (400 MHz, CD₂Cl₂): δ=2.24 (s, 3H), 6.76 (d, 1H), 7.13 (s, 1H),7.15 (d, 1H), 7.18-7.26 (m, 4H), 7.31 (d, 2H), 7.40 (t, 2H), 8.22 (d,1H), 9.54 (s, 1H).

6.3 Intermediate 3

Intermediate 2 (736 mg, 2.42 mmol) is suspended in 30 mL of methanol.After adding 10 mL of THF the solid is solved in an ultrasonic bath.Saturated ammonia chloride solution (4 mL) is added and zinc powder (380mg, 5.8 mmol) is added at room temperature. The yellow reaction mixtureis stirred at room temperature for 18 h. Then 20 mL of THF andadditional zinc powder (380 mg, 5.8 mmol) are added. After keeping thereaction mixture in an ultrasonic bath, the mixture is stirred at roomtemperature overnight. The solvent is evaporated and the residue isdiluted in dichloromethane (50 mL). The suspension is filtered overcelite and washed with dichloromethane. The filtrate is washed withwater and then dried over Na₂SO₄. The desired product is obtained as ayellow solid (97%, 640 mg). ¹H-NMR (400 MHz, CD₂Cl₂): δ=2.28 (s, 3H),3.84 (s, 2H), 5.26 (s, 1H), 6.79 (m, 3H), 6.85 (d, 1H), 6.96 (d, 1H),7.10 (s, 1H), 7.15-7.25 (m, 6H).

6.4 Intermediate 4

Intermediate 3 (0.27 g, 1.0 mmol), 2-bromotoluene (0.17 g, 1.0 mmol) andpotassium carbonate (0.19 g, 1.4 mmol) in t-butanol (10 mL) is added2-(Dicyclohexylphosphino)-3,6-dimethoxy-2,4,6-tri-Isopropyl-1,1-biphenyl(0.027 g, 0.05 mmol) and2-Chloro-[2-(Dicyclohexylphosphino)-3,6-dimethoxy-2,4,6-tri-Isopropyl-1,1-biphenyl]-[2-(2-aminoethyl)phenyl]palladium(I)(0.040 g, 0.05 mmol) under argon atmosphere. The reaction mixture isstirred at 40° C. for 30 minutes, then heated to 80° C. and stirredovernight. After cooling to room temperature the reaction mixture isdiluted with dichloromethane and water. After separation of the layers,the organic layer is washed several times with water and then dried withanhydrous sodium sulphate. The organic layers are concentrated and theresidue is purified via column chromatography (silica, eluent:cyclohexane/ethyl acetate). The desired product is obtained in 97% yield(0.35 g).

6.5 Intermediate 5

Intermediate 4 (2.0 g, 5.5 mmol) is suspended in 70 mL of acetonitrileand purged with argon. Then the mixture is cooled to 0° C.(Chlormethyl)-dimethylammonium chloride (2.11 g, 16.5 mmol) is added.The resulting solution is allowed to reach room temperature overnightwhile stirring. The mixture is cooled again to 0° C. and sodium iodide(2.47 g, 16.5 mmol), suspended in 10 mL of acetonitrile, is added. Ayellow precipitate is forming. After stirring at 0° C. for 5 h thesuspension is filtered and the solid is washed with acetonitrile. Thefiltrate is diluted with dichloromethane. The combined organic layersare washed several times with water, then dried over Na₂SO₄ andconcentrated under vacuum. The desired product is obtained as a yellowsolid in 95% yield (2.6 g). ¹H-NMR (400 MHz, CD₂Cl₂): δ=2.26 (s, 3H),2.35 (s, 3H), 7.21-7.32 (m, 4H), 7.49 (d, 1H), 7.52-7.61 (m, 2H),7.62-7.77 (m, 6H), 7.93 (d, 1H), 8.10 (d, 2H), 10.84 (s, 1H).

6.6 Intermediate 6

Intermediate 5 (1.0 g, 2.0 mmol) is solved in 60 mL of methanol andcooled to 0° C. Sodium methanolate (0.44 g, 2.4 mmol) in methanol isadded dropwise. The mixture is stirred and allowed to reach roomtemperature overnight. The obtained suspension is cooled to 0° C. andfiltered. The solid is washed two times with cold methanol and is thendried at 40° C. overnight. The desired product is obtained as acolorless solid (0.63 g, 64%). ¹H-NMR (400 MHz, CD₂Cl₂): δ=2.29 (s, 3H),2.33 (s, 3H), 3.23 (s, 3H), 6.38 (d, 1H), 6.68 (d, 1H), 6.81 (s, 1H),7.06-7.49 (m, 11H), 7.56 (d, 2H).

6.7 Complex 6 (Mer Isomer)

Intermediate 6 (0.61 g, 1.5 mmol) is solved in o-xylene (78 mL).Molecular sieves (5Å and 3Å, 0.5 g each),chloro([1,5]cyclooctadien)Iridium(I)-dimer (0.17 g, 0.25 mmol) and DMF(13 mL) are added to the solution. After purging with an argon flux for5 minutes, the reaction is heated at 140° C. for 15 h. After cooling toroom temperature, the solids are removed by filtration and washed witho-xylene. The filtrate is concentrated under vacuum and then purifiedseveral times via column chromatography (silica, eluent: 1×cyclohexane/dichloromethane; 2× toluene). The desired product isobtained in 4 isomers. MALDI-MS 1312

Photoluminescence (2% film in PMMA): λ_(max)=428 nm; τ₀=3.8 μs;PLQY=42%.

7 Synthesis of

Complex 7; Mer Complex 7.1 Intermediate 1

Under argon atmosphere N-phenyl-o-diaminobenzene (23.0 g, 122 mmol) and2-brombiphenyl (29.1 g, 122 mmol) are suspended in toluene (275 mL). Tothis mixture xantphos (97%, 4.38 g, 7.34 mmol), Pd₂(dba)₃ (2.24 g, 2.45mmol), NaO_(t)Bu (11.8 g, 122 mmol) and water (1.5 mL) are added. Thereaction is stirred at reflux overnight. The reaction is cooled to roomtemperature and purged with argon for 10 minutes. Then additionalxantphos (2.18 g, 3.67 mmol) and Pd₂(dba)₃ (1.11 g, 1.22 mmol) areadded. The reaction is heated to reflux and stirred overnight. Then thereaction is again cooled to room temperature and purged with argon for10 minutes. Then additional xantphos (2.18 g, 3.67 mmol) and Pd₂(dba)₃(1.11 g, 1.22 mmol) are added for the third time. The reaction is heatedto reflux and stirred overnight. After cooling to room temperature thesuspension is filtered under vacuum and washed with toluene. Thefiltrate is concentrated under vacuum. The residue is purified viacolumn chromatography (silica, cyclohexane/dichloromethane) and thedesired product is obtained in 94% yield (39 g). ¹H-NMR (400 MHz,CD₂Cl₂): δ=5.68 (d, 2H), 6.81-6.90 (m, 3H), 7.00 (m, 3H), 7.02 (d, 1H),7.13-7.25 (q, 6H), 7.27-7.44 (m, 5H).

7.2 Intermediate 2

Intermediate 1 (600 mg, 1.8 mmol) is suspended in 5 mL oftriethylorthoformate under argon atmosphere. To this mixture NH₄BF₄ (190mg, 1.8 mmol) is added. The reaction is kept under reflux for 15 h.After cooling to room temperature the reaction mixture is diluted withCH₂Cl₂ and evaporated under vacuum. The brown residue is suspended inMeOtBu and ethyl acetate (10 mL, each) and is filtered and washed withMeOtBu. The product is dried at 45° C. for 15 h to give a solid (93%,720 g). ¹H-NMR (400 MHz, DMSO): δ=7.16-7.32 (m, 5H), 7.44 (d, 1H), 7.56(t, 1H), 7.65 (t, 1H), 7.70-7.94 (m, 9H), 7.99 (d, 1H), 10.51 (s, 1H).

7.3 Complex 7 (Mer Isomer)

Tetrafluoroborate salt B (2.00 g, 4.61 mmol) is suspended in toluene (30mL) and potassium hexamethyldisilizan (KHMDS, 0.5 M in toluene, 9.2 mL,4.6 mmol) added dropwise over 25 min. The reaction mixture is stirredfor 30 minutes at room temperature and then transferred dropwise within20 minutes to a mixture ofdi-μ-chloro-bis[(cycloocta-1,5-dien)-iridium(I)] (310 mg, 0.46 mmol) intoluene (30 mL). The reaction mixture is heated reflux for 18 h. Aftercooling to room temperature the suspension is filtered and the residueis washed with toluene. The combined organic layers are concentrated.The formed solid is dissolved in dichloromethane (20 mL) and ethanol (40ml). Solvent is removed until a precipitate is formed, which is filteredand washed with ethanol. This procedure is repeated for a second time.Then the solid is suspended in THF (30 mL), the residue filtered and thefiltrate is slightly concentrated to yield a second portion of solid,which both contain the merdional isomer of the complex (21%).

Photoluminescence (2% film in PMMA): λ_(max)=434 nm; τ₀=17 μs; PLQY=27%.

8 Synthesis of

Complex 8; Mer Complex 8.1 Intermediate 1

In 36 mL of toluene 2-chloro-3-iodopyridine (1.4 g, 6.0 mmol) and (1.0g, 5.7 mmol) 2-aminobiphenyl are added under argon atmosphere. Thesuspension is degassed 10 min with argon flux, then BINAP (112 mg, 0.18mmol) and Pd(OAc)₂ (40 mg, 0.18 mmol) are added. The suspension isstirred a few minutes then cesium carbonate (9.7 g, 30 mmol) andtriethyl amine (550 mg, 5.4 mmol) are added. The suspension is stirredfor 5 minutes at room temperature and is then heated to reflux. Thereaction is stirred for 4h, then BINAP (112 mg, 0.18 mmol) and Pd(OAc)₂(40 mg, 0.18 mmol) are added. After stirring over night at reflux, againBINAP (112 mg, 0.18 mmol) and Pd(OAc)₂ (40 mg, 0.18 mmol) are added. Thereaction is stirred at reflux for 15 h. After cooling to roomtemperature, the suspension is filtered under vacuum and washed withtoluene. The filtrate is concentrated to 3 mL. The residue is dilutedwith methanol. A brown precipitate is formed. After filtration thefiltrate is concentrated. The residue is purified via columnchromatography (silica, eluent: cyclohexane/dichloromethane) and thedesired product is obtained in 77% yield (1.24 g). ¹H-NMR (400 MHz,CD₂Cl₂): δ=6.10 (s, 1H), 7.03-7.10 (m, 1H), 7.15-7.24 (m, 1H), 7.32-7.48(m, 9H), 7.79 (d, 1H).

8.2 Intermediate 2

Intermediate 1 (14.3 g, 50.8 mmol) and aniline (5.06 g, 54.3 mmol) aresuspended in 175 mL of toluene. The mixture is degassed for 10 minuteswith argon. Then BINAP (1.42 g, 2.28 mmol) and Pd₂(dba)₃ (697 mg, 0.761mmol) are added. The mixture is stirred a 5 minutes at room temperature.Then sodium tert-butyl at (7.04 g, 71.1 mmol) is added. After stirringfor 5 min at room temperature, the mixture is heated to reflux for 15 h.After cooling to room temperature the suspension is filtered and washedwith toluene. The filtrate is concentrated. The residue is charged oncelite and purified via column chromatography (silica, eluenttoluene/ethyl acetate). The obtained product fractions are concentratedunder reduced pressure. The solid is solved in dichloromethane anddiluted with the same amount of methanol. After removing a part of thesolvent a white precipitate is formed. The solid is filtered and washedwith methanol. The desired product is obtained in 45% yield (7.76 g).¹H-NMR (400 MHz, CD₂Cl₂): δ=5.29 (s, 1H), 6.71 (d, 1H), 6.73-6.79 (m,1H), 6.91-7.00 (m, 3H), 7.18 (t, 1H), 7.21-7.30 (q, 3H), 7.34-7.42 (m,2H), 7.44-7.57 (m, 6H), 8.05 (d, 1H).

8.3 Intermediate 3

Intermediate 2 (7.70 g, 22.8 mmol) is suspended in 180 mL ofhydrochloric acid (32%) at room temperature. The suspension is stirredat room temperature for 15 h. After treatment in an ultrasonic bath themixture is stirred at 30° C. for 15 h. The suspension is filtered andthe residue is washed with water. After drying at 45° C. the desiredproduct is obtained in 96% yield (8.22 g). ¹H-NMR (400 MHz, CD₂Cl₂):δ=4.38 (s, 1H), 6.69 (t, 1H), 6.96 (d, 1H), 7.20-7.35 (m, 7H), 7.35-7.44(m, 4H), 7.45-7.56 (m, 4H), 8.08 (s, 1H), 10.09 (s, 1H),

8.4 Intermediate 4

Intermediate 3 (300 mg, 0.80 mmol) is suspended in 5 mL of triethylortho formate. The reaction is heated to reflux and stirred for 15 h.After cooling to room temperature the suspension is filtered and washeda few times with ethyl acetate. The solid is dried at 45° C. undervacuum. The desired product is obtained in 84% yield (260 mg). ¹H-NMR(400 MHz, DMSO): δ=7.20-7.30 (m, 3H), 7.36 (d, 2H), 7.58-7.65 (q, 1H),7.69-7.87 (m, 5H), 7.91 (t, 1H), 7.97 (t, 3H), 8.05 (d, 1H), 8.73 (d,1H), 10.90 (s, 1H).

8.5 Complex 8 (Mer Isomer)

Intermediate 4 (3.38 g, 8.81 mmol) is suspended in 100 mL of anhydrousacetonitrile. The suspension is sparkled with argon flux for 10 minutes.Then silver oxide (1.03 g, 4.40 mmol) is added to the suspension and thereaction is stirred at room temperature for 18 h. The suspension isevaporated under reduced pressure. The solid is diluted with anhydrouso-xylene, then [Ir(COD)Cl]₂ (600 mg, 0.88 mmol) is added. Under an argonflux the reaction is heated to reflux for 18 h. After cooling to roomtemperature the brown reaction mixture is filtered under vacuum. Thefiltrate is evaporated and the residue is solved in a few mL ofdichloromethane. This solution is diluted with 100 mL of ethanol, whilea solid is formed. The precipitate is filtered and dried at 40° C. Themixture is purified via column chromatography (silica, eluent:cyclohexane/ethyl acetate) to yield the product as light yellow solid(0.53 g, 25%).

Photoluminescence (2% film in PMMA): λ_(max)=455 nm; τ₀=1.3 μs;PLQY=79%.

9 Synthesis of

Complex 9; Mer Complex 9.1 Intermediate 1

1-Amino-2-chloropyrazine (4.64 g, 22.6 mmol), 2-aminobiphenyl (4.72 g,22.1 mmol) and cesium carbonate (8.82 g, 27.1 mmol) are suspended in 125mL of THF under argon atmosphere. The suspension is degassed 10 minutesunder argon flux. Then BrettPhos (250 mg, 0.45 mmol) and BrettPhosPalladacycle (370 mg, 0.45 mmol) are added. The suspension is stirred afew minutes at room temperature and is then heated to reflux for 18 h.After cooling to room temperature the reaction mixture is filtered oversilica gel and washed with THF. The filtrate is evaporated under vacuum.The residue is stirred in 50 mL of acetonitrile. The suspension isfiltered and the residue is washed twice with a few mL of acetonitrile.The solid is dried at 45° C. under reduced pressure. The solid isrecrystallized (100 mL of acetonitrile, drying at 45° C.) to yield theproduct in 58% yield (4.48 g). ¹H-NMR (400 MHz, CD₂Cl₂): δ=6.09 (s, 1H),6.28 (s, 1H), 7.00 (t, 1H), 7.12 (t, 1H), 7.17 (d, 2H), 7.26 (t, 3H),7.30-7.44 (m, 6H), 7.73 (d, 2H), 7.83 (d, 1H).

9.2 Intermediate 2

Intermediate 1 (1.00 g, 2.96 mmol) is suspended in 65 mL of hydrochloricacid (32%) at room temperature under nitrogen atmosphere. The mixture isstirred for 2h at room temperature. Then the mixture is poured into 200mL of water. The yellow precipitate is filtered and washed with water.After drying at 45° C. the desired product is obtained in 81% yield(0.81 g). ¹H-NMR (400 MHz, CD₂Cl₂): δ=7.05-7.10 (m, 2H), 7.22-7.28 (m,1H), 7.30-7.36 (m, 4H), 7.40 (d, 1H), 7.45-7.53 (m, 6H), 7.75 (d, 2H),9.60 (br.s, 1H), 10.50 (br.s, 1H).

9.3 Intermediate 3

Intermediate 2 (975 mg, 2.27 mmol) is suspended in 42 mL oftriethylorthoformate. The reaction is stirred for 1 h at roomtemperature, then 2h at 50° C. and then 2h at 70° C. Then the reactionis stirred at room temperature overnight. The reaction is concentratedunder vacuum. The yellow residue is suspended in ethanol andsonificated. The solid is filtered and washed with anhydrous ethanol.After drying at 40° C. the desired product is obtained in 77% yield (0.8g). ¹H-NMR (400 MHz, CD₂Cl₂): δ=0.87 (t, 3H), 3.10-3.29 (m, 2H), 6.27(s, 1H), 7.10 (t, 1H), 7.24-7.38 (m, 8H), 7.41 (d, 1H), 7.45-7.55 (m,3H), 7.57-7.69 (d, 2H).

9.4 Complex 9 (Mer Isomer)

Intermediate 3 (660 mg, 1.67 mmol) and [Ir(COD)Cl]₂ (112.38 mg, 0.167mmol) are suspended in 10 mL of anhydrous o-xylene. The reaction issparkled with argon for 10 minutes and then heated to reflux for 18 h.After cooling to room temperature, the suspension is filtered and thefiltrate is evaporated under vacuum. The brown residue is suspended in10 mL of ethanol. The solid is filtered and washed with a few mL ofethanol. The solid is solved in dichloromethane and diluted withethanol. The solution is evaporated under vacuum until a yellowprecipitate is formed. This mixture is stirred at room temperature for18 h. After filtering the suspension, the solid is washed with a few mLof ethanol. Then the product is purified via column chromatography(silica, eluent: cyclohexane/ethyl acetate). The product is isolated in17% yield (69 mg).

Maldi-MS 1235 (M+H)

Photoluminescence (2% film in PMMA): λ_(max)=521 nm; τ₀=1.3 μs;PLQY=63%.

B Device Examples

Device examples: all initial performance given at 1000 cd/m²

1 OLED Comprising Complex 1 as Emitter (E-X)

40 nm HIL Plexcore AJ20-1000-10 nm Ir(DPBIC)₃:MoO₃ (50:50)-10 nmIr(DPBIC)₃-40 nm E-X/Ir(DPBIC)₃/SH-2 (10:10:80)-5 nm SH-2-25 nmETM-2:Liq (50:50)-4 nm KF-100 nm Al

LT₅₀ Voltage CurrEff LumEff EQE [relative Example E-X [V] [cd/A] [lm/W][%] CIE x, y value]¹⁾ Device 1.1 Complex 1 5.3 44.7 26.4 13.9 0.34; 0.562500% ¹⁾in view of the OLED in example 3 with complex 3 V as E-X

2 OLED Comprising Complex 1 or 2 as Emitter (E-X)

40 nm HIL Plexcore AJ20-1000-10 nm Ir(DPBIC)₃:MoO₃ (90:10)-10 nmIr(DPBIC)₃-40 nm E-X/Ir(DPBIC)₃/SH-2 (10:10:80)-5 nm SH-2-20 nmETM-2:Liq (50:50)-4 nm KF-100 nm Al

LT₅₀ Voltage CurrEff LumEff EQE [relative Example E-X [V] [cd/A] [lm/W][%] CIE x, y values]¹⁾ Device 2.1 Complex 2 5.9 43.6 23.4 13.9 0.32;0.55 1500% Device 2.2 Complex 1 5.1 45.1 27.8 14.1 0.35; 0.56 2200% ¹⁾inview of the OLED in example 3 with complex 3 V as E-X

3 OLED Comprising Complex 3 or 3V (Comparative Example) as Emitter (E-X)

40 nm HIL Plexcore AJ20-1000-10 nm Ir(DPBIC)₃:NDP-9 (99:1)-10 nmIr(DPBIC)₃-40 nm 018742/Ir(DPBIC)₃/SH-2 (10:10:80)-5 nm SH-2-25 nmETM-2:Liq (50:50)-4 nm KF-100 nm Al

LT₅₀ Voltage CurrEff LumEff EQE [relative Example E-X [V] [cd/A] [lm/W][%] CIE x, y value] Device Complex 3 V 4.8 41.3 27.1 17.2 0.21; 0.38100% 3.1 (comp. example) Device Complex 3 4.5 42.1 29.1 15.8 0.23; 0.44490% 3.2

Comparative Complex 3V:

(described in WO 2012/172482)

4 OLED Comprising Complexes 5 or 9 as Emitter (E-X)

40 nm HIL Plexcore AJ20-1000-10 nm Ir(DPBIC)₃:MoO₃ (90:10)-10 nmIr(DPBIC)₃-40 nm E-X/Ir(DPBIC)₃/SH-2 (10:10:80)-5 nm SH-2-20 nmETM-2:Liq (50:50)-4 nm KF-100 nm Al

Device 4.1: E-X: Complex 5

Device 4.2: E-X: Complex 9

Luminescent OLEDs with long lifetimes are obtained in examples 4.1 and4.2.

5 OLED Comprising Complexes 4 or 8 as Emitter (E-X)

40 nm HIL Plexcore AJ20-1000-10 nm Ir(DPBIC)₃:MoO₃ (90:10)-10 nmIr(DPBIC)₃-40 nm E-X/Ir(DPBIC)₃/SH-2 (10:10:80)-5 nm Host-X-20 nmETM-2:Liq (50:50)-4 nm KF-100 nm Al

Device 5.1: E-X: Complex 4

Device 5.2: E-X: Complex 8

Luminescent OLEDs with long lifetimes are obtained in examples 5.1 and5.2.

6 OLED Comprising Complex 4 (Mer) or 4V (Comparative Example) as Emitter(E-X)

ITO 120 nm-Ir(DPBIC)₃:MoO₃ (90:10) 90 nm-Ir(DPBIC)₃ 10 nm-Emitter:Host-X (% Host-X=100%-% Emitter) 40 nm-Host-X 5 nm-ETM-2:Liq (50:50) 25nm-KF 4 nm-Alu

LT₅₀ Voltage CurrEff LumEff [relative Emitter % Emitter [V] [cd/A][lm/W] EQE [%] CIEx CIEy value] 4 V 30 5.22 16.46 9.91 12.65 0.152 0.167100% 4 30 5.35 12.86 7.55 8.72 0.161 0.190 367% 4 V 40 4.72 18.73 12.4613.23 0.152 0.188 100% 4 40 5.25 12.68 7.58 7.65 0.167 0.229 300%

Diaryl substituted, yet meridional, emitters show better lifetime inOLEDs than those with mono-aryl-monoalkyl substituted meridionalemitters.

Comparative Complex 4V:

(mer Em-2, described in WO 2012/172482)

Host-X in devices 5.1 and 5.2 and 6 has the following formula:

(published in WO2009/003898, compound 4g),

SH-2 and ETM-2 employed in the devices mentioned above have thefollowing formulae:

The invention claimed is:
 1. A cyclometallated Ir complex of formula (I)

wherein A¹ is CH or N; A² is CR¹ or N; A³ is CR² or N; wherein in thecase that A¹ and/or A³ are N, A² is CR¹; R¹, R², R³, R⁴, R⁶ and R⁷ areeach independently hydrogen; deuterium; a linear or branched,substituted or unsubstituted alkyl radical having from 1 to 20 carbonatoms, optionally interrupted by at least one heteroatom, selected fromO, S and N; a substituted or unsubstituted cycloalkyl radical having atotal of from 3 to 30 carbon atoms; a substituted or unsubstitutedheterocyclo alkyl radical, interrupted by at least one heteroatomselected from O, S and N and having a total of from 3 to 30 carbon atomsand/or heteroatoms; a substituted or unsubstituted aryl radical, havinga total of from 6 to 30 carbon atoms; a substituted or unsubstitutedheteroaryl radical, having a total of from 5 to 30 carbon atoms and/orheteroatoms, selected from O, S and N; or a group with donor or acceptoraction; or R¹ and R², R³ and R⁴ and/or R⁶ and R⁷ may form, independentlyof each other, together with the carbon atoms to which they are bonded,a saturated or unsaturated or aromatic, optionally substituted ring,which is optionally interrupted by at least one heteroatom, selectedfrom O, S and N, has a total of from 5 to 18 carbon atoms and/orheteroatoms, and may optionally be fused to at least one furtheroptionally substituted saturated or unsaturated or aromatic ring,optionally interrupted by at least one heteroatom, selected from O, Sand N, and having a total of from 5 to 18 carbon atoms and/orheteroatoms; R⁵ is a linear or branched, substituted or unsubstitutedalkyl radical having from 1 to 20 carbon atoms, optionally interruptedby at least one heteroatom, selected from O, S and N; a substituted orunsubstituted cycloalkyl radical having a total of from 3 to 30 carbonatoms; a substituted or unsubstituted heterocyclo alkyl radical,interrupted by at least one heteroatom selected from O, S and N andhaving a total of from 3 to 30 carbon atoms and/or heteroatoms; asubstituted or unsubstituted aryl radical, having a total of from 6 to30 carbon atoms; a substituted or unsubstituted heteroaryl radical,having a total of from 5 to 30 carbon atoms and/or heteroatoms, selectedfrom O, S and N; or a group with donor or acceptor action; X is CH, CDor N; Y is CR⁸ or N; R⁸ is hydrogen; deuterium; a linear or branched,substituted or unsubstituted alkyl radical having from 1 to 20 carbonatoms, optionally interrupted by at least one heteroatom, selected fromO, S and N; a substituted or unsubstituted cycloalkyl radical having atotal of from 3 to 30 carbon atoms; a substituted or unsubstitutedheterocyclo alkyl radical, interrupted by at least one heteroatomselected from O, S and N and having a total of from 3 to 30 carbon atomsand/or heteroatoms; a substituted or unsubstituted aryl radical, havinga total of from 6 to 30 carbon atoms; a substituted or unsubstitutedheteroaryl radical, having a total of from 5 to 30 carbon atoms and/orheteroatoms, selected from O, S and N; or a group with donor or acceptoraction.
 2. The cyclometallated Ir complex according to claim 1, whereinR¹, R², R³, R⁴, R⁶ and R⁷ are each independently hydrogen; deuterium;methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl, sec-butyl,iso-butyl, cyclopentyl, cyclohexyl, OCH₃, OCF₃; phenyl, pyridyl,pyrimidyl, pyrazinyl, carbazolyl, dibenzofuranyl, dibenzothiophenyl,benzofuranyl and benzothiophenyl wherein the aforementioned radicals maybe unsubstituted or substituted by methyl, ethyl, n-propyl, iso-propyl,n-butyl, tert-butyl, sec-butyl, iso-butyl, methoxy, CF₃ or phenyl; or agroup with donor or acceptor action, selected from F, CF₃, CN and SiPh₃;and R⁵ is methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl,sec-butyl, iso-butyl, cyclopentyl, cyclohexyl, OCH₃, OCF₃; phenyl,pyridyl, pyrimidyl, pyrazinyl, wherein the aforementioned radicals maybe substituted by methyl, ethyl, n-propyl, iso-propyl, n-butyl,tert-butyl, sec-butyl, iso-butyl, methoxy or phenyl or unsubstituted; ora group with donor or acceptor action, selected from CF₃ and CN.
 3. Thecyclometallated Ir complex according to claim 1, wherein R¹, R², R³, R⁴,R⁶ and R⁷ are each independently hydrogen; deuterium; methyl, ethyl,n-propyl, iso-propyl, n-butyl, tert-butyl, sec-butyl, iso-butyl; phenyl,pyridyl, pyrimidyl, pyrazinyl, carbazolyl, dibenzofuranyl,dibenzothiophenyl, wherein the aforementioned radicals may beunsubstituted or substituted by methyl, ethyl, iso-propyl, tert-butyl,iso-butyl or methoxy; CF₃ or CN; and R⁵ is methyl, ethyl, n-propyl,iso-propyl, n-butyl, sec-butyl, iso-butyl; phenyl, tolyl or pyridyl. 4.The cyclometallated Ir complex according to claim 1, wherein X, Y areeach independently CH, CD or N.
 5. The cyclometallated Ir complexaccording to claim 1, wherein X is N; and Y is CR⁸.
 6. Thecyclometallated Ir complex according to claim 1, wherein X is N; and Yis N.
 7. The cyclometallated Ir complex according to claim 1, wherein Xis CH or CD; and Y is CR⁸.
 8. The cyclometallated Ir complex accordingto claim 1, having one of the following formulae


9. An organic electronic device comprising at least one cyclometallatedIr complex according to claim
 1. 10. The organic electronic deviceaccording to claim 9, wherein the organic electronic device is selectedfrom an organic light-emitting diode (OLED), a light-emittingelectrochemical cell (LEEC), an organic photovoltaic cell (OPV) and anorganic field-effect transistor (OFET).
 11. The organic electronicdevice according to claim 9, wherein the cyclometallated Ir complex offormula (I) is employed in OLEDs or LEECs or in OPVs.
 12. The organicelectronic device according to claim 11, wherein the OLED comprises (a)an anode, (b) a cathode, (c) a light-emitting layer between the anodeand the cathode, (d) optionally a hole transport layer between thelight-emitting layer and the anode, wherein the cyclometallated Ircomplex of formula (I) is present in the light-emitting layer and/or—ifpresent—in the hole transport layer of the OLED.
 13. The organicelectronic device according to claim 9, wherein the cyclometallated Ircomplex of formula (I) is employed in combination with at least one hostmaterial.
 14. A light-emitting layer comprising at least onecyclometallated Ir complex of formula (I) as defined in claim 1 asemitter material.
 15. An organic light-emitting diode (OLED) comprisinga cyclometallated Ir complex of formula (I) as defined in claim
 1. 16.An apparatus comprising the organic electronic device according to claim9, wherein the apparatus is selected from the group consisting of astationary visual display unit; a mobile visual display unit; anillumination unit; a unit in items of clothing; a unit in handbags, aunit in accessories, a unit in furniture and a unit in wallpaper.
 17. Aprocess for preparing a cyclometallated Ir complex of formula (I) asdefined in claim 1, by contacting suitable compounds comprising Ir withappropriate ligands or ligand precursors.
 18. An organic electronicdevice comprising at least one cyclometallated Ir complex selected fromthe group consisting of: